JP7578483B2 - Semiconductor element forming method and substrate processing apparatus - Google Patents

Description

The present invention relates to a semiconductor device forming method and a substrate processing apparatus.

Substrate processing apparatuses that process substrates are used, for example, in the formation of semiconductor elements. In recent years, in order to manufacture fine memory elements for semiconductor elements, progress has been made in forming memory elements by stacking them on a semiconductor substrate (see Patent Document 1). In the semiconductor memory element of Patent Document 1, holes with a large aspect ratio, known as memory holes, are formed in the stacked structure of the semiconductor substrate in the direction perpendicular to the base material. A large number of memory elements are arranged side by side within the holes.

JP 2019-117894 A

In the semiconductor memory element of Patent Document 1, the diameter of the lower part of the memory hole is smaller than the diameter of the upper part of the memory hole. This is because the etching solution is less likely to reach the lower part of the memory hole than the upper part of the memory hole. In this case, there is a risk of variation in the electrical characteristics of the memory element formed in the memory hole. The aspect ratio of memory holes (the ratio of the height to the width of the memory hole) is increasing year by year, and in recent years there are memory holes with an aspect ratio of more than 50. In memory holes with such a high aspect ratio, it is not easy to align the diameter of the upper part of the memory hole with the diameter of the lower part of the memory hole.

In addition, with the recent trend toward miniaturization of elements and three-dimensionalization of element structures, similar problems occur not only in the memory holes described above, but also in recesses such as holes or trenches with a large aspect ratio. That is, the etching solution does not penetrate as easily below the recess compared to above it, and liquid replacement does not progress as easily, so the lower part of the recess is etched differently from the upper part of the recess. Thus, in recesses such as holes and trenches with a relatively large aspect ratio (hereinafter referred to as recesses), the diameter of the recess may not be constant within the recess.

The present invention has been made in consideration of the above problems, and its purpose is to provide a semiconductor element forming method and substrate processing apparatus that can adjust the diameter of a recess provided in a layered structure of a substrate by selectively etching the recess.

According to one aspect of the present invention, a method for forming a semiconductor device includes the steps of forming a coating layer that selectively covers a portion of a recess located on a surface side of a laminate structure supported by a substrate, and etching the deep portion of the recess with a chemical solution so as to widen the diameter of the portion of the recess deeper than the coating layer. The step of forming the coating layer includes the steps of forming a filling layer that fills the recess, and after forming the filling layer, heating the filling layer while the filling layer is in contact with an aqueous solution to partially remove the portion of the filling layer located on the surface side of the filling layer to form a partial filling layer that partially fills the deep portion of the recess, supplying a water repellent after forming the partial filling layer, and supplying the water repellent to form the coating layer on the surface side of the recess, and then removing the partial filling layer and the water repellent .

In one embodiment, the step of removing the partial filling layer includes a step of supplying a removal liquid to dissolve the partial filling layer.

In one embodiment, the step of partially removing the filling layer includes the step of supplying a removal liquid that removes the filling layer.

In one embodiment, in the etching step, the chemical solution contains hydrofluoric acid, water, or phosphoric acid.

In one embodiment, a plurality of memory elements are formed in the recess.

In one embodiment, the laminated structure has a plurality of recesses as the recess, and a difference in top diameter between the recesses is 5% or less.

In one embodiment, the recesses are regularly arranged in the laminate structure .

In one embodiment, an etch stop layer is disposed between the substrate and the laminate structure.

In one embodiment, an acidic aqueous solution is supplied as the aqueous solution in the step of forming the partial filling layer.

According to another aspect of the present invention, a substrate processing apparatus includes a processing liquid supply unit, a water repellent supply unit, a chemical liquid supply unit, an aqueous solution supply unit, a heating mechanism, and a control unit. The processing liquid supply unit supplies a processing liquid. The water repellent supply unit supplies a water repellent. The chemical liquid supply unit supplies a chemical liquid. The aqueous solution supply unit supplies an aqueous solution. The heating mechanism heats a filling layer formed from the processing liquid. The control unit controls the processing liquid supply unit, the water repellent supply unit, the chemical liquid supply unit, the aqueous solution supply unit, and the heating mechanism. The control unit controls the processing liquid supply unit, the water repellent supply unit, the chemical liquid supply unit, the aqueous solution supply unit, and the heating mechanism to (1) supply the processing liquid to form a filling layer that fills the recess provided in the laminate structure supported by the substrate, (2) after forming the filling layer, heat the filling layer with the heating mechanism while the filling layer is in contact with the aqueous solution supplied from the aqueous solution supply unit, thereby partially removing the portion located on the surface side of the filling layer and forming a partial filling layer that partially fills the deep portion of the recess, (3) supply the water repellent to form a coating layer that selectively covers the portion of the recess located on the surface side that is not covered by the partial filling layer, and (4) supply the chemical liquid to expand the diameter of the portion of the recess deeper than the coating layer.

In one embodiment, the heating mechanism heats the packed bed with heat or light.

In one embodiment, the heating mechanism includes a heater.

In one embodiment, the heating mechanism includes a lamp.

In one embodiment, the heating mechanism includes a heat medium supply unit that supplies a heat medium, and the heat medium includes heated nitrogen gas.

In one embodiment, the aqueous solution supply unit supplies an acidic aqueous solution as the aqueous solution.

According to the present invention, the diameter of the recess provided in the laminated structure of the substrate can be adjusted.

1 is a schematic diagram of a substrate processing apparatus according to an embodiment of the present invention; 1 is a schematic diagram of a substrate processing apparatus according to an embodiment of the present invention; 1 is a block diagram of a substrate processing apparatus according to an embodiment of the present invention; 1A is a schematic side view of a semiconductor element manufactured using the substrate processing apparatus of this embodiment, FIG. 1B is a schematic top view of the semiconductor element, and FIG. 1C is an enlarged view of a portion of FIG. 1A to 1E are schematic diagrams illustrating a semiconductor device forming method according to an embodiment of the present invention. 1A to 1G are schematic diagrams illustrating a semiconductor device forming method according to an embodiment of the present invention. FIG. 2 is a flow diagram of a semiconductor device forming method according to the present embodiment. FIG. 2 is a flow diagram of a semiconductor device forming method according to the present embodiment. 1 is a schematic diagram of a substrate processing apparatus according to an embodiment of the present invention; FIG. 2 is a flow diagram of a semiconductor device forming method according to the present embodiment. 1 is a schematic diagram of a substrate processing apparatus according to an embodiment of the present invention; FIG. 2 is a flow diagram of a semiconductor device forming method according to the present embodiment. 1 is a schematic diagram of a substrate processing apparatus according to an embodiment of the present invention; FIG. 2 is a flow diagram of a semiconductor device forming method according to the present embodiment. 1 is a schematic diagram of a substrate processing apparatus according to an embodiment of the present invention; FIG. 2 is a flow diagram of a semiconductor device forming method according to the present embodiment. 1 is a schematic diagram of a substrate processing apparatus according to an embodiment of the present invention; FIG. 2 is a flow diagram of a semiconductor device forming method according to the present embodiment. 1 is a schematic diagram of a substrate processing apparatus according to an embodiment of the present invention; 1 is a schematic diagram of a semiconductor element formed by the semiconductor element forming method of the present embodiment.

Hereinafter, an embodiment of a semiconductor element forming method and a substrate processing apparatus according to the present invention will be described with reference to the drawings. In the drawings, the same or corresponding parts are denoted by the same reference symbols and will not be described repeatedly. In this specification, mutually orthogonal X-axis, Y-axis, and Z-axis may be described in order to facilitate understanding of the invention. Typically, the X-axis and Y-axis are parallel to the horizontal direction, and the Z-axis is parallel to the vertical direction. In addition, in this specification, mutually orthogonal x-axis, y-axis, and z-axis may be described in order to facilitate understanding of the invention. Typically, the x-axis and y-axis extend parallel to the main surface of the substrate or base material, and the z-axis extends perpendicular to the main surface of the substrate or base material.

First, an embodiment of a substrate processing apparatus 100 according to the present invention will be described with reference to FIG. 1. FIG. 1 is a schematic plan view of the substrate processing apparatus 100 according to the present embodiment.

The substrate processing apparatus 100 processes the substrate W. The substrate processing apparatus 100 processes the substrate W by performing at least one of etching, surface treatment, property imparting, treatment film formation, removal of at least a portion of the film, and cleaning.

The substrate W is used as a semiconductor substrate. The substrate W includes a semiconductor wafer. For example, the substrate W is substantially disk-shaped. Here, the substrate processing apparatus 100 processes the substrates W one by one.

As shown in FIG. 1, the substrate processing apparatus 100 includes multiple chambers 110, a fluid cabinet 100A, a fluid box 100B, multiple load ports LP, an indexer robot IR, a center robot CR, and a control device 101. The control device 101 controls the load ports LP, the indexer robot IR, and the center robot CR. The control device 101 includes a control unit 102 and a memory unit 104.

Each of the load ports LP accommodates multiple stacked substrates W. The indexer robot IR transports substrates W between the load ports LP and the center robot CR. The center robot CR transports substrates W between the indexer robot IR and the chambers 110. Each of the chambers 110 discharges liquid onto the substrate W to process the substrate W. The liquid includes a processing liquid, a removal liquid, a water repellent agent and/or a chemical liquid. The fluid cabinet 100A accommodates liquid. The fluid cabinet 100A may also accommodate gas.

Specifically, the multiple chambers 110 form multiple towers TW (four towers TW in FIG. 1) arranged to surround the center robot CR in a plan view. Each tower TW includes multiple chambers 110 (three chambers 110 in FIG. 1) stacked vertically. Each fluid box 100B corresponds to a multiple tower TW. The liquid in the fluid cabinet 100A is supplied to all chambers 110 included in the tower TW corresponding to the fluid box 100B via one of the fluid boxes 100B. Also, the gas in the fluid cabinet 100A is supplied to all chambers 110 included in the tower TW corresponding to the fluid box 100B via one of the fluid boxes 100B.

The control device 101 controls various operations of the substrate processing device 100.

The control device 101 includes a control unit 102 and a memory unit 104. The control unit 102 has a processor. The control unit 102 has, for example, a central processing unit (CPU). Alternatively, the control unit 102 may have a general-purpose computing unit.

The memory unit 104 stores data and computer programs. The data includes recipe data. The recipe data includes information indicating a plurality of recipes. Each of the plurality of recipes specifies the processing content and processing procedure for the substrate W.

The storage unit 104 includes a main storage device and an auxiliary storage device. The main storage device is, for example, a semiconductor memory. The auxiliary storage device is, for example, a semiconductor memory and/or a hard disk drive. The storage unit 104 may include removable media. The control unit 102 executes a computer program stored in the storage unit 104 to perform substrate processing operations.

Next, the substrate processing apparatus 100 of this embodiment will be described with reference to FIG. 2. FIG. 2 is a schematic diagram of the substrate processing apparatus 100.

The substrate processing apparatus 100 includes a chamber 110, a substrate holding unit 120, and a liquid supply unit 130. The chamber 110 accommodates a substrate W. The substrate holding unit 120 holds the substrate W.

The chamber 110 is generally box-shaped with an internal space. The chamber 110 accommodates the substrate W. Here, the substrate processing apparatus 100 is a single-wafer type that processes the substrate W one by one, and the chamber 110 accommodates the substrate W one by one. The substrate W is accommodated in the chamber 110 and processed in the chamber 110. The chamber 110 accommodates at least a portion of each of the substrate holding unit 120 and the liquid supply unit 130.

The substrate holding part 120 holds the substrate W. The substrate holding part 120 holds the substrate W horizontally so that the top surface (front surface) Wa of the substrate W faces upward and the back surface (bottom surface) Wb of the substrate W faces vertically downward. The substrate holding part 120 also rotates the substrate W while holding it. The top surface Wa of the substrate W has a layered structure in which a recess is formed, as will be described in detail later. The substrate holding part 120 rotates the substrate W while holding it.

For example, the substrate holding unit 120 may be of a clamping type that clamps the edge of the substrate W. Alternatively, the substrate holding unit 120 may have any mechanism that holds the substrate W from the back surface Wb. For example, the substrate holding unit 120 may be of a vacuum type. In this case, the substrate holding unit 120 holds the substrate W horizontally by adsorbing the center of the back surface Wb of the substrate W, which is the non-device formation surface, to its upper surface. Alternatively, the substrate holding unit 120 may combine a clamping type that brings multiple chuck pins into contact with the peripheral edge surface of the substrate W, with a vacuum type.

For example, the substrate holding unit 120 includes a spin base 121, a chuck member 122, a shaft 123, an electric motor 124, and a housing 125. The chuck member 122 is provided on the spin base 121. The chuck member 122 chucks the substrate W. Typically, the spin base 121 is provided with a plurality of chuck members 122.

The shaft 123 is a hollow shaft. The shaft 123 extends vertically along the rotation axis Ax. The spin base 121 is coupled to the upper end of the shaft 123. The substrate W is placed above the spin base 121.

The spin base 121 is disk-shaped and supports the substrate W horizontally. The shaft 123 extends downward from the center of the spin base 121. The electric motor 124 provides a rotational force to the shaft 123. The electric motor 124 rotates the shaft 123 in a rotational direction, thereby rotating the substrate W and the spin base 121 around the rotation axis Ax. The housing 125 surrounds the shaft 123 and the electric motor 124.

The liquid supply unit 130 supplies liquid to the substrate W. Typically, the liquid supply unit 130 supplies liquid to the upper surface Wa of the substrate W.

The liquid supply unit 130 includes a treatment liquid supply unit 132, a removal liquid supply unit 134, a water repellent supply unit 136, and a chemical liquid supply unit 138. At least a portion of the treatment liquid supply unit 132, the removal liquid supply unit 134, the water repellent supply unit 136, and the chemical liquid supply unit 138 are housed within the chamber 110.

The processing liquid supply unit 132 supplies a processing liquid to the upper surface Wa of the substrate W. For example, the processing liquid contains a solute and a volatile solvent. After the processing liquid is supplied to the upper surface Wa of the substrate W, the solvent evaporates, forming a filling layer from the solute. The filling layer is a solid film made of solute components. The filling layer can retain particles remaining in the recesses of the substrate W. When the filling layer is formed, particles adhering to the upper surface Wa of the substrate W are detached from the substrate W and retained in the filling layer.

Here, "solidification" refers to the solidification of a solute due to forces acting between molecules or atoms as the solvent evaporates, for example. "Hardening" refers to the solidification of a solute due to chemical changes such as polymerization or crosslinking, for example. Therefore, "solidification or hardening" refers to the "solidification" of a solute due to various factors. Note that the treatment liquid only needs to solidify or harden to an extent that it can hold particles, and the solvent does not need to evaporate completely. In addition, the "solute component" that forms the filling layer may be the solute itself contained in the treatment liquid, or it may be something derived from the solute, for example, something obtained as a result of a chemical change.

As the solute, various resins can be used that are soluble in any solvent and that, when solidified or cured, can form a filling layer while separating and holding particles adhering to the upper surface of the substrate W from the substrate W. For example, as the solute, a resin (hereinafter sometimes referred to as a "heat-sensitive water-soluble resin") that is poorly soluble or insoluble in water before being heated to a predetermined alteration temperature or higher, and that is altered to become water-soluble when heated to the alteration temperature or higher, can be used.

As a heat-sensitive water-soluble resin, for example, a resin that decomposes when heated to a predetermined deterioration temperature or higher (e.g., 200°C or higher), exposing polar functional groups and becoming water-soluble can be used. When heated to a temperature above the deterioration temperature, the heat-sensitive water-soluble resin becomes water-soluble.

However, the temperature of the heat-sensitive water-soluble resin may be kept below its alteration temperature to form the filling layer while maintaining its poor solubility or insolubility in aqueous liquids. When forming the filling layer, the temperature of the processing liquid is set below the alteration temperature of the heat-sensitive water-soluble resin, so that a filling layer that is poorly soluble or insoluble in aqueous liquids is formed on the upper surface of the substrate W without altering the heat-sensitive water-soluble resin to become water-soluble. In this case, the filling layer that maintains its clump state can be removed from the substrate W without causing particles to fall off from the filling layer. Therefore, particles can be removed at a high removal rate.

In addition to the heat-sensitive water-soluble resin, the solute contained in the treatment liquid may be, for example, acrylic resin, phenolic resin, epoxy resin, melamine resin, urea resin, unsaturated polyester resin, alkyd resin, polyurethane, polyimide, polyethylene, polypropylene, polyvinyl chloride, polystyrene, polyvinyl acetate, polytetrafluoroethylene, acrylonitrile butadiene styrene resin, acrylonitrile styrene resin, polyamide, polyacetal, polycarbonate, polyvinyl alcohol, modified polyphenylene ether, polybutylene terephthalate, polyethylene terephthalate, polyphenylene sulfide, polysulfone, polyether ether ketone, polyamide imide, etc.

The solvent preferably has a higher volatility than water. It is preferable to use PGEE (propylene glycol monoethyl ether) as the solvent.

The treatment liquid may also contain a sublimable substance. As the sublimable substance, various substances that have a high vapor pressure at 5°C to 35°C and change from a solid phase to a gas phase without passing through a liquid phase are used. As the sublimable substance, for example, hexamethylenetetramine, 1,3,5-trioxane, 1-pyrrolidinecarbodithioate ammonium, metaldehyde, paraffin having about 20 to 48 carbon atoms, t-butanol, paradichlorobenzene, naphthalene, L-menthol, fluorohydrocarbon compounds, etc. can be used. In particular, as the sublimable substance, fluorohydrocarbon compounds can be used.

As the fluorohydrocarbon compound, for example, one or more of the following compounds (A) to (E) can be used.
Compound (A): Fluoroalkane having 3 to 6 carbon atoms, or a derivative thereof. Compound (B): Fluorocycloalkane having 3 to 6 carbon atoms, or a derivative thereof. Compound (C): Fluorobicycloalkane having 10 carbon atoms, or a derivative thereof. Compound (D): Fluorotetracyanoquinodimethane, or a derivative thereof. Compound (E): Fluorocyclotriphosphazene, or a derivative thereof.

The compound (A) may be a fluoroalkane having 3 to 6 carbon atoms represented by the formula (1) or a derivative thereof.
C _m H _n F2 _m+2-n (1)
(In the formula, m is a number from 3 to 6, and n is a number in the range of 0≦n≦2m+1.)

It is particularly preferable to use 1,1,2,2,3,3,4-heptafluorocyclopentane as the sublimable substance. This compound has a vapor pressure of approximately 8266 Pa at 20°C, a melting point (freezing point) of 20.5°C, and a boiling point of 82.5°C. When mixing a sublimable substance in a molten state, a solvent that is compatible with the sublimable substance in a molten state is preferable. When dissolving a sublimable substance as a solute, a solvent that is soluble in the sublimable substance is preferable.

When mixing a sublimable substance in a molten state, the solvent is preferably one that is compatible with the sublimable substance in a molten state. When dissolving a sublimable substance as a solute, the solvent is preferably one that is soluble in the sublimable substance.

The solvent may be, for example, at least one selected from the group consisting of DIW, pure water, aliphatic hydrocarbons, aromatic hydrocarbons, esters, alcohols, ethers, etc. Specifically, for example, DIW, pure water, methanol, ethanol, IPA, butanol, ethylene glycol, propylene glycol, NMP (N-methyl-2-pyrrolidone), DMF (N,N-dimethylformamide), DMA (dimethylacetamide), DMSO (dimethylsulfoxide), hexane, toluene, PGMEA (propylene glycol monomethyl ether acetate), PGME (propylene glycol monomethyl ether), PGPE (propylene glycol monopropyl ether), PGEE (propylene glycol monoethyl ether), GBL (γ-butyrolactone), acetylacetone, 3-pentanone, 2-heptanone, ethyl lactate, cyclohexanone, dibutyl ether, HFE (hydrofluoroether), ethyl nonafluoroisobutyl ether, ethyl nonafluorobutyl ether, and m-xylene hexafluoride are at least one selected from the group consisting of.

In addition to the above, other solutes contained in the treatment solution include polymers containing protective groups that dissociate with acid. Copolymers having acrylate as a structural unit are also suitable.

The processing liquid supply unit 132 includes a pipe 132a, a valve 132b, and a nozzle 132n. The nozzle 132n ejects processing liquid onto the upper surface Wa of the substrate W. The nozzle 132n is connected to the pipe 132a. Processing liquid is supplied to the pipe 132a from a supply source. The valve 132b opens and closes the flow path in the pipe 132a. It is preferable that the nozzle 132n is configured to be movable relative to the substrate W.

The removing liquid supply unit 134 supplies a removing liquid to the upper surface Wa of the substrate W. The removing liquid can remove a filling layer formed from the solute of the processing liquid. By controlling the time for which the removing liquid is supplied, the filling layer can be selectively removed from the substrate W.

As the removal liquid, any solvent that dissolves any of the resins can be used. As the removal liquid, for example, organic solvents such as thinner, toluene, acetates, alcohols, and glycols, and acidic liquids such as acetic acid, formic acid, and hydroxyacetic acid can be used. In particular, it is preferable to use a solvent that is compatible with water-based liquids. For example, it is preferable to use isopropyl alcohol (IPA) as the removal liquid. Furthermore, an alkaline aqueous solution can be used as the removal liquid. For example, as the alkaline aqueous solution, inorganic alkalis such as sodium hydroxide, potassium hydroxide, sodium carbonate, and sodium silicate, organic amines such as ammonia, ethylamine, propylamine, diethylamine, diethylaminoethanol, and triethylamine, and quaternary amines can be used.

The removing liquid supply unit 134 includes a pipe 134a, a valve 134b, and a nozzle 134n. The nozzle 134n ejects the removing liquid onto the upper surface Wa of the substrate W. The nozzle 134n is connected to the pipe 134a. The removing liquid is supplied to the pipe 134a from a supply source. The valve 134b opens and closes the flow path in the pipe 134a. It is preferable that the nozzle 134n is configured to be movable relative to the substrate W.

The water repellent supply unit 136 supplies liquid water repellent to the upper surface Wa of the substrate W. By supplying the water repellent, a water repellent layer is formed on the upper surface Wa of the substrate W.

For example, the water repellent agent includes a compound having a methyl group or a silyl group at its terminal. Typically, hydroxyl groups (OH groups) are present on the surface of the recess, and the water repellent agent replaces the hydroxyl groups on the surface of the substrate W with methyl groups or silyl groups. It is preferable that the water repellent agent does not change the properties of the filling layer.

For example, the water repellent is a water repellent that makes silicon (Si) itself and compounds containing silicon hydrophobic. Typically, the water repellent is a silane coupling agent. In one example, the silane coupling agent includes at least one of HMDS (hexamethyldisilazane), TMS (tetramethylsilane), fluorinated alkylchlorosilane, alkyldisilazane, and non-chloro water repellent. The non-chloro water repellent includes at least one of dimethylsilyldimethylamine, dimethylsilyldiethylamine, hexamethyldisilazane, tetramethyldisilazane, bis(dimethylamino)dimethylsilane, N,N-dimethylaminotrimethylsilane, N-(trimethylsilyl)dimethylamine, and an organosilane compound.

The water repellent supply unit 136 includes a pipe 136a, a valve 136b, and a nozzle 136n. The nozzle 136n ejects the water repellent onto the upper surface Wa of the substrate W. The nozzle 136n is connected to the pipe 136a. The water repellent is supplied to the pipe 136a from a supply source. The valve 136b opens and closes the flow path in the pipe 136a. It is preferable that the nozzle 136n is configured to be movable relative to the substrate W.

The chemical liquid supply unit 138 supplies a chemical liquid to the upper surface Wa of the substrate W. The upper surface Wa of the substrate W can be chemically processed by chemical processing using the chemical liquid. By chemical processing, it is possible to perform any one of etching, surface treatment, imparting properties, forming a processed film, and removing at least a portion of a film on the substrate W. Typically, the chemical liquid is an etching liquid used in the etching process of the substrate W.

The chemical solution contains hydrofluoric acid. For example, the hydrofluoric acid may be heated to 40°C or higher and 70°C or lower, or to 50°C or higher and 60°C or lower. However, the hydrofluoric acid does not have to be heated. The chemical solution may also contain water or phosphoric acid.

The chemical solution may further contain hydrogen peroxide. The chemical solution may also contain SC1 (ammonia hydrogen peroxide mixture), SC2 (hydrochloric acid hydrogen peroxide mixture), or aqua regia (a mixture of concentrated hydrochloric acid and concentrated nitric acid).

The chemical liquid supply unit 138 includes a pipe 138a, a valve 138b, and a nozzle 138n. The nozzle 138n ejects the chemical liquid onto the upper surface Wa of the substrate W. The nozzle 138n is connected to the pipe 138a. The chemical liquid is supplied to the pipe 138a from a supply source. The valve 138b opens and closes the flow path in the pipe 138a. It is preferable that the nozzle 138n is configured to be movable relative to the substrate W.

As described above, the nozzles 132n, 134n, 136n, and 138n of the processing liquid supply unit 132, the removal liquid supply unit 134, the water repellent supply unit 136, and the chemical liquid supply unit 138 may be movable. The nozzles 132n, 134n, 136n, and 138n can move horizontally and/or vertically according to a movement mechanism controlled by the control unit 102. Please note that the movement mechanism has been omitted in this specification to avoid overly complicated drawings.

The substrate processing apparatus 100 further includes a cup 180. The cup 180 recovers liquid that has splashed from the substrate W. The cup 180 rises and falls. For example, the cup 180 rises vertically upward to the side of the substrate W during the period in which the liquid supply unit 130 supplies liquid to the substrate W. In this case, the cup 180 recovers liquid that splashes from the substrate W due to the rotation of the substrate W. In addition, when the period in which the liquid supply unit 130 supplies liquid to the substrate W ends, the cup 180 descends vertically downward from the side of the substrate W.

As described above, the control device 101 includes the control unit 102 and the memory unit 104. The control unit 102 controls the substrate holder 120, the processing liquid supply unit 132, the removal liquid supply unit 134, the water repellent supply unit 136, and/or the cup 180. In one example, the control unit 102 controls the electric motor 124, the valves 132b, 134b, 136b, and/or 138b.

The substrate processing apparatus 100 of this embodiment is suitable for use in the manufacture of semiconductor devices having semiconductors. Typically, in semiconductor devices, a conductive layer and an insulating layer are stacked on a substrate. The substrate processing apparatus 100 is suitable for use in cleaning and/or processing (e.g., etching, changing characteristics, etc.) the conductive layer and/or insulating layer during the manufacture of semiconductor devices.

Next, the substrate processing apparatus 100 of this embodiment will be described with reference to Figures 1 to 3. Figure 3 is a block diagram of the substrate processing apparatus 100.

As shown in FIG. 3, the control device 101 controls various operations of the substrate processing apparatus 100. The control device 101 controls the indexer robot IR, the center robot CR, the substrate holding unit 120, and the liquid supply unit 130. Specifically, the control device 101 controls the indexer robot IR, the center robot CR, the substrate holding unit 120, and the liquid supply unit 130 by sending control signals to the indexer robot IR, the center robot CR, the substrate holding unit 120, and the liquid supply unit 130.

Specifically, the control unit 102 controls the indexer robot IR to transfer the substrate W by the indexer robot IR.

The control unit 102 controls the center robot CR to transfer the substrate W by the center robot CR. For example, the center robot CR receives an unprocessed substrate W and transports the substrate W into one of the multiple chambers 110. The center robot CR also receives a processed substrate W from the chamber 110 and transports the substrate W out.

The control unit 102 controls the substrate holding unit 120 to start rotation of the substrate W, change the rotation speed, and stop rotation of the substrate W. For example, the control unit 102 can control the substrate holding unit 120 to change the rotation speed of the substrate holding unit 120. Specifically, the control unit 102 can change the rotation speed of the substrate W by changing the rotation speed of the electric motor 124 of the substrate holding unit 120.

The control unit 102 can separately control the valves 132b, 134b, 136b, and 138b of the liquid supply unit 130 to switch the states of the valves 132b, 134b, 136b, and 138b between an open state and a closed state. Specifically, the control unit 102 can control the valves 132b, 134b, 136b, and 138b of the liquid supply unit 130 to open the valves 132b, 134b, 136b, and 138b, thereby allowing the processing liquid, removal liquid, water repellent, and chemical liquid flowing through the pipes 132a, 134a, 136a, and 138a to pass toward the nozzles 132n, 134n, 136n, and 138n. In addition, the control unit 102 can control the valves 132b, 134b, 136b, and 138b of the liquid supply unit 130 to close the valves 132b, 134b, 136b, and 138b, thereby stopping the supply of the processing liquid, removal liquid, water repellent, and chemical liquid flowing through the pipes 132a, 134a, 136a, and 138a toward the nozzles 132n, 134n, 136n, and 138n, respectively.

The substrate processing apparatus 100 of this embodiment is suitable for use in forming semiconductor elements. For example, the substrate processing apparatus 100 is suitable for use in processing a substrate W used as a semiconductor element having a stacked structure. The semiconductor element is a so-called 3D structure memory (storage device). As an example, the substrate W is suitable for use as a NAND type flash memory.

Next, referring to FIG. 4, a substrate W fabricated as a semiconductor element 300 using the substrate processing apparatus 100 of this embodiment will be described. FIG. 4(a) is a schematic side view of the semiconductor element 300 fabricated by processing the substrate W using the substrate processing apparatus 100, FIG. 4(b) is a schematic top view of the semiconductor element 300, and FIG. 4(c) is an enlarged view of a portion of FIG. 4(b). In FIG. 4, the direction perpendicular to the main surface of the base material S of the substrate W is indicated as the z direction, and the directions perpendicular to the z direction are indicated as the x direction and the y direction.

As shown in FIG. 4(a), the substrate W has a base material S and a laminated structure L. The base material S is a thin film extending in the xy plane. The laminated structure L is formed on the upper surface of the base material S. The base material S supports the laminated structure L. The laminated structure L is formed to extend in the z direction from the upper surface of the base material S.

4A further includes an etching stop layer Es between the base material S and the laminated structure L. The etching stop layer Es is made of, for example, _alumina ( _Al2O3 ). As will be described in detail later, the laminated structure L is partially removed by etching to form a recess R. The progress of etching is stopped by the etching stop layer Es.

The laminated structure L has an insulating layer N and a conductive layer M. The insulating layer N and the conductive layer M are laminated alternately. For example, the insulating layer N is formed from a silicon oxide film. The conductive layer M is formed from a metal. For example, the conductive layer M contains tungsten (W).

Each of the multiple insulating layers N extends parallel to the upper surface of the substrate S. Multiple conductive layers M are provided between two adjacent insulating layers N. The two adjacent insulating layers N are supported by the conductive layers M.

For example, the thickness (length along the z direction) of the insulating layer N is 1 nm or more and 50 nm or less. Also, for example, the thickness (length along the z direction) of the conductive layer M is 1 nm or more and 50 nm or less.

The sum of the thickness of one insulating layer N and the thickness of one conductive layer M is 20 nm or more and 100 nm or less. The laminated structure L has 10 to 100 insulating layers N and 10 to 100 conductive layers M.

The laminated structure L has a recess R. The recess R extends in a direction perpendicular to the main surface of the substrate S. The recess R extends between the surface La of the laminated structure L and the etching stop layer Es.

The diameter (diameter) of the recess R is on the nano-order. For example, the diameter of the recess R is 20 nm or more and 300 nm or less. The diameter of the recess R may be 50 nm or more and 200 nm or less.

Ideally, the recess R is formed perpendicular to the main surface of the substrate S. The diameter of the surface portion of the recess R (top diameter Wt) is 20 nm or more and 300 nm or less, and 50 nm or more and 200 nm or less.

For example, the aspect ratio of the recess R is 10 or more. Also, so far, it has been reported that a memory hole with a height of about 1 μm can be formed with an aspect ratio of 40 to 50, and it is expected that the aspect ratio will increase further in the future. For example, the upper limit of the aspect ratio of the recess R may be 100 or 200.

In the semiconductor element 300 shown in FIG. 4(a), a cylindrical charge retention layer H is disposed within a recess R in a substrate W. A cylindrical channel layer Ch is disposed inside the charge retention layer H. For example, the channel layer Ch is formed from polysilicon. A cylindrical dielectric layer D is disposed inside the channel layer Ch. The dielectric layer D is formed from a silicon oxide film.

The charge retention layer H may have a three-layer structure. For example, the charge retention layer H includes a cylindrical inner layer H1, a cylindrical middle layer H2, and a cylindrical outer layer H3. The outer layer H3 contacts the laminated structure L. The middle layer H2 is disposed inside the outer layer H3. The inner layer H1 is disposed inside the middle layer H2. The inner layer H1 contacts the channel layer Ch. Therefore, from the center of the recess R of the laminated structure L, the dielectric layer D, the channel layer Ch, the inner layer H1, the middle layer H2, and the outer layer H3 are disposed.

For example, the inner layer H1 is formed from a silicon oxide film. The inner layer H1 is also called a tunnel layer.

For example, the intermediate layer H2 is formed from a silicon nitride film. The intermediate layer H2 accumulates electric charges. The intermediate layer H2 is also called a charge accumulation layer.

For example, the outer layer H3 is formed from a silicon oxide film. The outer layer H3 is also called a block layer.

When a voltage is applied to the conductive layer M and the channel layer Ch, charge is stored in the corresponding intermediate layer H2. As shown in FIG. 4(a), a memory element Se is formed corresponding to the conductive layer M. Therefore, the number of memory elements Se formed in one recess R corresponds to the number of conductive layers M.

As shown in FIG. 4(b), a plurality of recesses R are formed in the substrate W, and the recesses R are regularly arranged on the substrate W. A charge retention layer H, a channel layer Ch, and a dielectric layer D are arranged in each recess R. The recesses R are designed to have the same diameter and height. For example, the difference in the top diameter Wt of each recess R may be 5% or less, or may be 3% or less.

Typically, the recess R is formed by performing dry etching on the stacked structure L. When forming the recess R by performing dry etching on the stacked structure L, the diameter of the deep portion of the recess R may become smaller than the diameter of the surface side of the recess R. In particular, as the height of the stacked structure and/or the number of layers in the stacked structure increases, the diameter of the deep portion of the recess R tends to become smaller than the diameter of the surface side of the recess R. In addition, the shorter the processing period of the dry etching is in order to improve throughput, the more likely the diameter of the deep portion of the recess R tends to become smaller than the diameter of the surface side of the recess R.

As shown in FIG. 4(a), multiple memory elements Se are formed in the recess R. For this reason, it is preferable that the diameter of the recess R is constant from the surface side portion to the deep portion. However, when the recess R is formed in the stacked structure L, the diameter of the recess R may not be constant. If the diameter of the recess R varies, when the memory elements are formed in the recess R, the electrical characteristics of the memory elements may not be constant, and the characteristics of the memory elements may not be uniform.

In addition, in general, the smaller the diameter of the recess R, the more memory elements can be formed on the substrate, so a small diameter of the recess R is preferable in order to increase memory capacity. However, if the diameter of the recess R is small, the flow of the etching fluid for etching the recess R is likely to be insufficient. For this reason, when the recess R is etched, etching tends to be biased depending on the position of the recess R. Specifically, the surface side portion of the recess R is relatively easily etched, whereas the deeper portion of the recess R is relatively difficult to etch.

As will be described in detail later, according to this embodiment, even if the diameter of the recess R is small, the deep portion Rf of the recess R can be selectively etched. This makes it possible to suppress non-uniformity in the diameter of the recess R.

Next, the semiconductor device forming method of this embodiment will be described with reference to FIG. 5. A part of the semiconductor device forming method of this embodiment is performed using the substrate processing apparatus 100 described above with reference to FIGS. 1 to 3.

As shown in FIG. 5(a), the substrate W has a base material S and a laminated structure L. The base material S is a thin film extending in the xy plane. The laminated structure L is formed on the upper surface of the base material S. The laminated structure L is formed so as to extend in the z direction from the upper surface of the base material S. For example, the laminated structure L is formed from a silicon oxide film and a silicon nitride film. The laminated structure L has a surface La.

The laminated structure L has an insulating layer N and a sacrificial layer Sa. The insulating layers N and the sacrificial layers Sa are alternately laminated. Each of the multiple insulating layers N extends parallel to the upper surface of the substrate S. Multiple sacrificial layers Sa are provided between two adjacent insulating layers N. The two adjacent insulating layers N are supported by the sacrificial layers Sa. The sacrificial layers Sa are replaced by the conductive layers M shown in FIG. 4 during the process of fabricating the semiconductor element 300.

For example, the thickness (length along the z direction) of the insulating layer N is 1 nm or more and 50 nm or less. The insulating layer N is formed of a silicon oxide film.

For example, the thickness (length along the z direction) of the sacrificial layer Sa is 1 nm or more and 50 nm or less. For example, the sacrificial layer Sa is formed from a material that is etched when an etching solution that does not substantially etch the insulating layer N is used. In one example, the sacrificial layer Sa is formed from a silicon nitride film. For example, when phosphoric acid is used as the etching solution, the sacrificial layer Sa can be etched without substantially etching the insulating layer N.

As shown in FIG. 5(b), a recess R is formed in the stacked structure L. Typically, the recess R is formed by dry etching. Ideally, the diameter (length in the xy plane) of the recess R formed by dry etching is constant from the surface side to the deep part, but in reality, the diameter of the recess R may not be constant from the surface side to the deep part. In particular, when the processing time of the dry etching is shortened to improve the throughput of the substrate W, it is difficult for the diameter of the recess R to be constant from the surface side to the deep part. In this case, the diameter of the deep part Rf of the recess R is smaller than the diameter of the surface side portion Rn of the recess R.

As shown in FIG. 5(c), the recess R of the substrate W is deformed. For example, the diameter of the deep portion Rf of the recess R is selectively made larger than the diameter of the deep portion Rf of the recess R after dry etching. In one example, the diameter of the deep portion Rf of the recess R is expanded over a length of less than 10 nm along the xy plane. This makes it possible to make the diameter of the recess R of the substrate W uniform from the surface side to the deep portion.

As shown in FIG. 5(d), a charge retention layer H is formed inside the recess R of the laminated structure L.

As shown in FIG. 5(e), a channel layer Ch and a dielectric layer D are formed inside the charge retention layer H. Then, the sacrificial layer Sa is replaced with a conductive layer M. In this manner, the semiconductor element 300 shown in FIG. 4 can be formed.

In FIG. 5B, in order to avoid overly complicated explanation, the diameter of the recess R is shown to change linearly from the surface side to the depth, but this embodiment is not limited to this. Due to the bowing phenomenon, the diameter of the recess R may be largest near the center.

Next, the semiconductor element forming method of this embodiment will be described with reference to Figures 1 to 3 and Figure 6. Figures 6(a) to 6(g) are schematic diagrams for explaining the semiconductor element forming method of this embodiment. The semiconductor element forming method shown in Figures 6(a) to 6(g) is preferably used as part of the semiconductor element forming method described above with reference to Figure 5. For example, the semiconductor element forming method shown in Figures 6(a) to 6(g) is performed for the modification of the recess R shown in Figure 5(c). The semiconductor element forming method of this embodiment is performed using the substrate processing apparatus 100 described above with reference to Figures 1 to 3.

As shown in FIG. 6(a), a recess R is provided in the laminate structure L. For example, the recess R is formed in the laminate structure L by etching the substrate W. Here, the recess R is formed in the insulating layer N and the sacrificial layer Sa. The recess R reaches the etching stop layer Es.

As shown in FIG. 6(b), the recess R is filled with a filling layer F. The filling layer F is, for example, an organic material (carbon-based material). In one example, the filling layer F is a polymer. The filling layer F may be formed from a resist. For example, after the processing liquid supply unit 132 supplies the processing liquid to the substrate W, the solvent is volatilized from the processing liquid, and the filling layer F is formed from the solute of the processing liquid. Here, the filling layer F fills from the deep portion Rf of the recess R to the surface portion Rn.

It is preferable that the treatment liquid changes to a solid state after being applied to the substrate W. The treatment liquid itself is liquid, but after the treatment liquid is applied to the substrate W, the solvent evaporates, causing the solute to change to a solid state and form a filling layer F.

As shown in FIG. 6(c), a removing liquid Ds is applied to the substrate W. The removing liquid Ds dissolves the filling layer F. Here, the removing liquid Ds partially dissolves the filling layer F filled in the recess R. As a result, the surface side portion Rn of the recess R is replaced with the removing liquid Ds, while the deep portion Rf of the recess R remains filled with the filling layer F. As a result, a partial filling layer Fp that partially fills the deep portion Rf of the recess R is formed from the filling layer F.

For example, the removal liquid supply unit 134 supplies the removal liquid Ds to the substrate W. The removal liquid supply unit 134 supplies the removal liquid Ds for a time and in an amount set so that the filling layer F is partially dissolved without being completely dissolved. For example, the removal liquid Ds includes isopropyl alcohol (IPA).

Typically, more than half of the depth of the recess R is replaced with the removal liquid Ds, and less than half of the filling layer F of the depth of the recess R remains, forming a partial filling layer Fp. For example, the depth of the partial filling layer Fp (length in the z-axis direction) is 1/3 or less of the depth of the recess R.

As shown in FIG. 6(d), a water repellent agent P is supplied. For example, the water repellent agent supply unit 136 supplies the water repellent agent P to the substrate W. The partial filling layer Fp is not affected by the water repellent agent P, and the removal liquid Ds is replaced with the water repellent agent P. As a result, the removal liquid Ds in the surface side portion Rn of the recess R is replaced with the water repellent agent P, while the deep portion Rf of the recess R remains filled with the partial filling layer Fp.

The deep portion Rf of the recess R is covered with the partial filling layer Fp, but the surface side portion Rn of the recess R is not covered by the partial filling layer Fp. Therefore, when the water repellent P is supplied, the surface of the laminated structure L reacts with the water repellent P in the surface side portion Rn of the recess R to form a coating layer Ps.

As shown in FIG. 6(e), the partial filling layer Fp and the water repellent P are removed. In this case, a portion of the water repellent P on the surface side of the recess R is removed along with the partial filling layer Fp in the deep portion Rf of the recess R. At this time, it is preferable to also remove particles that are residues left when the recess R is formed (e.g., during dry etching). By removing the partial filling layer Fp, the insulating layer N and the sacrificial layer Sa are exposed in the deep portion Rf of the recess R. Meanwhile, the surface side portion Rn of the recess R remains covered with the covering layer Ps.

For example, a removal liquid may be applied to remove the partial filling layer Fp and the water repellent agent P. In one example, the removal liquid includes IPA. For example, the removal liquid supply unit 134 supplies the removal liquid Ds to the substrate W. The removal liquid supply unit 134 supplies the removal liquid for a time and in an amount set so that the partial filling layer Fp is completely dissolved.

Alternatively, the substrate W may be heated to remove the partial filling layer Fp and the water repellent agent P. For example, if the partial filling layer Fp is formed from a sublimable material, the partial filling layer Fp may be sublimated by heating.

As shown in FIG. 6(f), the recess R is etched with chemical solution C. Typically, chemical solution C contains hydrofluoric acid. For example, chemical solution C contains hydrofluoric acid diluted in the range of 1:100 to 1:2000. Alternatively, chemical solution C may contain water or deionized water (DIW). Alternatively, chemical solution C may contain phosphoric acid.

The deep portion Rf of the recess R is etched by the chemical solution C because the insulating layer N and the sacrificial layer Sa are exposed. On the other hand, the surface side portion Rn of the recess R is not etched by the chemical solution C because it is covered by the covering layer Ps. Therefore, as shown in FIG. 6(f), the region Re located in the deep portion Rf of the recess R is removed by the chemical solution C, and the diameter of the recess R is enlarged. The diameter of the deep portion Rf of the recess R may be enlarged so as to be equal to the diameter (top diameter) just before the recess R.

As shown in FIG. 6(g), the chemical solution C and the coating layer Ps are removed. The chemical solution C and the coating layer Ps may be removed by ultraviolet irradiation or heating. At this time, it is preferable that the residue from the dry etching is also removed. The chemical solution C and the coating layer Ps may be removed in an apparatus other than the substrate processing apparatus 100.

In this manner, the diameter of the recess R of the laminated structure L can be adjusted. Note that in Figs. 6(e), 6(f) and 6(g), the diameter of the deep portion Rf of the recess R is illustrated as being equal to the top diameter (aperture) of the recess R, while the diameter of the deep portion Rf of the recess R is larger than the diameter of the central portion of the recess R, so that the change in the shape of the recess R can be easily understood, but this is merely an example. The diameter of the deep portion Rf of the recess R may be enlarged so that the diameter of the deep portion Rf of the recess R is equal to the diameter of the central portion of the recess R. Alternatively, the recess R may be deformed so that the diameter of the deep portion Rf of the recess R is equal to the top diameter and the diameter of the central portion of the recess R.

In FIG. 6(c), the filling layer F is partially replaced with the removal liquid Ds by applying the removal liquid Ds. When the diameter of the recess R is small, it takes a relatively long time for the removal liquid Ds to remove the entire filling layer F. For this reason, the removal process of the filling layer F by the removal liquid Ds can be interrupted halfway through the time it takes for the removal liquid Ds to remove the entire filling layer F, thereby partially removing the filling layer F. Also, as shown in FIG. 6(c), by adjusting the amount of the removal liquid Ds and the processing time, etc., it is possible to leave a partial filling layer Fp that covers the appropriate parts.

In addition, in FIG. 6(c), the partial filling layer Fp is formed from the filling layer F by using the removal liquid Ds, but this embodiment is not limited to this. When the filling layer F is formed from a sublimable substance, the partial filling layer Fp may be formed from the filling layer F by heating. In this case, too, by adjusting the heating time and temperature, the partial filling layer Fp that partially fills the deep portion Rf of the recess R may be formed from the filling layer F.

The substrate W is preferably used as a memory having multiple memory elements Se. Typically, when the substrate W is used as a memory, the substrate W is provided with multiple recesses R designed to have a uniform diameter and height. Therefore, multiple recesses used in a memory with a large storage capacity can be simultaneously deformed by the same process.

When forming the recess R in the laminated structure L, the diameter of the recess R may be largest near the center due to the bowing phenomenon. In this case, it is preferable for the coating layer Ps to cover the center. In addition, the diameter of the deep portion Rf of the recess R may be widened by etching so that it becomes equal to the diameter of the recess R at its largest central portion.

In the above description with reference to FIG. 6, the coating layer Ps is formed by supplying a liquid water repellent P to the filled recess R of the partial filling layer Fp, but this embodiment is not limited to this. The coating layer Ps may be formed by a gas.

Next, the semiconductor device forming method of this embodiment will be described with reference to Figures 1 to 3, 6, and 7. Figure 7 is a flow diagram of the semiconductor device forming method. The semiconductor device forming method of this embodiment is preferably performed by the substrate processing apparatus 100 described above with reference to Figures 1 to 3.

First, in step S10, the recess R is partially covered with the laminated structure L. Typically, the surface side portion Rn of the recess R is selectively covered. For example, a covering layer Ps is formed on the surface side portion Rn of the recess R. The covering layer Ps selectively covers the surface side portion Rn of the recess R, but does not cover the deep portion Rf of the recess R. Therefore, the laminated structure L is exposed in the deep portion Rf of the recess R.

In step S20, the diameter of the deep portion Rf of the recess R is expanded. By applying the chemical solution C to the recess R, the diameter of the deep portion Rf of the recess R can be expanded. Since the recess R is partially covered with the coating layer Ps, the diameter of the deep portion Rf of the recess R that is not covered with the coating layer Ps is partially expanded. This allows the diameter of the deep portion Rf of the recess R to be expanded, and therefore the diameter of the recess R can be adjusted.

Next, the semiconductor device forming method of this embodiment will be described with reference to Figures 1 to 3 and Figures 6 to 8. Figure 8 is a flow diagram of the semiconductor device forming method. The semiconductor device forming method of this embodiment is preferably performed using the substrate processing apparatus 100 described above with reference to Figures 1 to 3.

First, in step Sa, the substrate W is loaded into the substrate processing apparatus 100. Here, the substrate W has a base material S and a laminated structure L, and a recess R is provided in the laminated structure L.

In step S10, the recess R is partially covered in the laminate structure L. Here, the partial coverage of the recess R in step S10 is achieved by forming a filling layer F in step S12, partially removing the filling layer F (forming a partial filling layer Fp) in step S14, supplying a water repellent in step S16, and removing the partial filling layer Fp in step S18.

In step S12, the recess R is filled with a filling layer F. The processing liquid supply unit 132 supplies the processing liquid to the substrate W. This causes the filling layer F to be filled into the recess R of the substrate W. Typically, after the processing liquid is supplied, the substrate holder 120 increases the rotation speed of the substrate W to shake off any excess processing liquid remaining on the surface of the substrate W to the outside of the substrate W.

In step S14, a portion of the filling layer F is removed. For example, the removal liquid supply unit 134 supplies the removal liquid to the substrate W for a predetermined period of time. The removal liquid Ds is applied to the filling layer F in the recess R, thereby partially dissolving the filling layer F and forming a partial filling layer Fp in the recess R. The time for applying the removal liquid Ds is set so as to partially remove the filling layer F in the recess R. At this time, the filling layer F in the surface side portion Rn of the recess R is removed, while the partial filling layer Fp remains in the deep portion Rf of the recess R.

Alternatively, a partial filling layer Fp may be formed in the recess R by heating the filling layer F for a predetermined period of time. For example, if the filling layer F contains a sublimable substance, a portion of the filling layer F can be sublimated by heating the filling layer F for a predetermined period of time, thereby forming a partial filling layer Fp in the recess R.

In step S16, a water repellent is supplied to the substrate W. The water repellent supply unit 136 supplies the water repellent to the substrate W. By applying the water repellent to the recess R in which the partial filling layer Fp is formed in the deep portion Rf, the water repellent is filled in the surface side portion Rn of the recess R where the partial filling layer Fp is not formed, and a water repellent layer is formed. At this time, the characteristics of the surface side portion Rn of the recess R are changed by the water repellent, and a coating layer Ps is formed on the surface side portion Rn of the recess R. In this way, by supplying the water repellent, a coating layer Ps is formed as part of the water repellent layer on the surface side portion Rn of the recess R.

In step S18, the partial filling layer Fp is removed. Here, the portion of the water-repellent layer formed from the water-repellent agent other than the coating layer Ps is removed, and the partial filling layer Fp is also removed. For example, the removal liquid supply unit 134 supplies a removal liquid to the substrate W to dissolve the partial filling layer Fp and replace the portion of the water-repellent layer other than the coating layer Ps. At this time, the surface side portion Rn of the recess R is covered with the coating layer Ps, while the laminated structure L is exposed in the deep portion Rf of the recess R.

Alternatively, the partial filling layer Fp may be removed by heating the partial filling layer Fp for a predetermined period of time. For example, if the filling layer F contains a sublimable substance, the partial filling layer Fp can be removed from the recess R by heating the filling layer F to sublimate a portion of the filling layer F.

Next, in step S20, the diameter of the deep portion Rf of the recess is expanded. For example, the chemical liquid supply unit 138 supplies a chemical liquid to the substrate W. This causes the deep portion Rf of the recess R that is not covered by the covering layer Ps to be partially etched, and the recess diameter is expanded.

In step Sb, the substrate W is removed from the substrate processing apparatus 100. Thereafter, the coating layer Ps is removed as necessary. The coating layer Ps may be removed by ashing the coating layer Ps by irradiation with ultraviolet light or by heat treatment. In this manner, a substrate W in which fluctuations in the recess diameter are suppressed can be formed.

In the above description with reference to FIG. 8, the etching in step S20 is performed with one type of etching solution, but this embodiment is not limited to this. The etching in step S20 may be performed with multiple types of etching solutions. For example, with one type of etching solution, the amount of etching of the insulating layer N may not be equal to the amount of etching of the sacrificial layer Sa. In this case, it is preferable to perform the etching in step S20 with multiple types of etching solutions.

Next, the semiconductor device forming method of this embodiment will be described with reference to Figures 1 to 3, 6, 9, and 10. Figure 9 is a schematic diagram of a substrate processing apparatus 100 of this embodiment. The substrate processing apparatus 100 of Figure 9 has a similar configuration to the substrate processing apparatus 100 shown in Figure 2, except that the liquid supply unit 130 further includes a rinsing liquid supply unit 137 and the chemical liquid supply unit 138 includes a first chemical liquid supply unit 138A and a second chemical liquid supply unit 138B, and therefore redundant descriptions will be omitted to avoid redundancy.

In the substrate processing apparatus 100, the liquid supply unit 130 further includes a rinse liquid supply unit 137. The rinse liquid supply unit 137 supplies a rinse liquid to the substrate W.

The rinse liquid supply unit 137 supplies a rinse liquid to the upper surface Wa of the substrate W. A rinse process using the rinse liquid can wash away chemicals and impurities adhering to the upper surface Wa of the substrate W. The rinse liquid supplied from the rinse liquid supply unit 137 may include any of deionized water (DIW), carbonated water, electrolytic ionized water, ozone water, ammonia water, hydrochloric acid water with a diluted concentration (e.g., about 10 ppm to 100 ppm), or reduced water (hydrogen water).

The rinsing liquid supply unit 137 includes a pipe 137a, a valve 137b, and a nozzle 137n. The nozzle 137n ejects the rinsing liquid onto the upper surface Wa of the substrate W. The nozzle 137n is connected to the pipe 137a. The rinsing liquid is supplied to the pipe 137a from a supply source. The valve 137b opens and closes the flow path in the pipe 137a. It is preferable that the nozzle 137n is configured to be movable relative to the substrate W.

In the substrate processing apparatus 100, the chemical liquid supply unit 138 includes a first chemical liquid supply unit 138A and a second chemical liquid supply unit 138B. The first chemical liquid supply unit 138A supplies the first chemical liquid to the substrate W. The second chemical liquid supply unit 138B supplies the second chemical liquid to the substrate W.

The first chemical liquid supply unit 138A supplies a first chemical liquid to the upper surface Wa of the substrate W. The upper surface Wa of the substrate W can be chemically processed by chemical processing using the first chemical liquid. The first chemical liquid supply unit 138A includes a pipe 138a, a valve 138b, and a nozzle 138n. The nozzle 138n ejects the first chemical liquid onto the upper surface Wa of the substrate W. The nozzle 138n is connected to the pipe 138a. The first chemical liquid is supplied to the pipe 138a from a supply source. The valve 138b opens and closes a flow path in the pipe 138a. It is preferable that the nozzle 138n is configured to be movable relative to the substrate W.

The second chemical liquid supply unit 138B supplies the second chemical liquid to the upper surface Wa of the substrate W. The upper surface Wa of the substrate W can be chemically processed by chemical processing using the second chemical liquid. The second chemical liquid supply unit 138B includes a pipe 138c, a valve 138d, and a nozzle 138m. The nozzle 138m ejects the second chemical liquid onto the upper surface Wa of the substrate W. The nozzle 138m is connected to the pipe 138c. The second chemical liquid is supplied to the pipe 138c from a supply source. The valve 138d opens and closes a flow path in the pipe 138c. It is preferable that the nozzle 138m is configured to be movable relative to the substrate W.

The etching selectivity of the first chemical liquid for the sacrificial layer Sa relative to the insulating layer N is different from the etching selectivity of the second chemical liquid for the sacrificial layer Sa relative to the insulating layer N. For example, when the etching ratio of the first chemical liquid for the sacrificial layer Sa relative to the insulating layer N is high, the etching ratio of the second chemical liquid for the sacrificial layer Sa relative to the insulating layer N is low. In one example, when the first chemical liquid contains hydrofluoric acid, it is preferable that the second chemical liquid contains water or phosphoric acid. In this way, by using the first and second chemical liquids having different etching selectivities of the sacrificial layer Sa relative to the insulating layer N, the amount of etching of the insulating layer N can be made equal to the amount of etching of the sacrificial layer Sa.

The control unit 102 can separately control the valves 137b, 138b, and 138d of the liquid supply unit 130 to switch the states of the valves 137b, 138b, and 138d between an open state and a closed state. Specifically, the control unit 102 can control the valves 137b, 138b, and 138d of the liquid supply unit 130 to open the valves 137b, 138b, and 138d, thereby passing the rinse liquid, the first chemical liquid, and the second chemical liquid flowing through the pipes 137a, 138a, and 138c toward the nozzles 137n, 138n, and 138m. Furthermore, the control unit 102 can control the valves 137b, 138b, and 138d of the liquid supply unit 130 to close the valves 137b, 138b, and 138d, thereby stopping the supply of the rinsing liquid, the first chemical liquid, and the second chemical liquid flowing through the pipes 137a, 138a, and 138c toward the nozzles 137n, 138n, and 138m, respectively.

Figure 10 is a flow diagram of the semiconductor element forming method of this embodiment. The flow diagram of Figure 10 is similar to the flow diagram of Figure 8, except that the etching of the deep portion Rf of the recess R is performed with multiple etching solutions, and duplicated descriptions are omitted to avoid redundancy.

In this embodiment, the etching in step S20 includes a first etching in step S20a, a rinse liquid supply in step S20b, and a second etching in step S20c. The selectivity of the etching of the sacrificial layer Sa relative to the insulating layer N is different for the first etching and the second etching. For example, when the etching ratio of the sacrificial layer Sa relative to the insulating layer N is high for the first etching, it is preferable that the etching ratio of the sacrificial layer Sa relative to the insulating layer N is low for the second etching.

In step S20a, the first etching selectively etches one of the insulating layer N and the sacrificial layer Sa. For example, the first chemical liquid supply unit 138A supplies the first chemical liquid to the upper surface Wa of the substrate W. When selectively etching the insulating layer N of the insulating layer N and the sacrificial layer Sa, it is preferable to use hydrofluoric acid as the first chemical liquid. When selectively etching the sacrificial layer Sa of the insulating layer N and the sacrificial layer Sa, it is preferable to use warm water or phosphoric acid as the first chemical liquid.

Then, in step S20b, a rinse process is performed. The rinse liquid supply unit 137 supplies a rinse liquid to the upper surface Wa of the substrate W.

In step S20c, the second etching selectively etches the other of the insulating layer N and the sacrificial layer Sa. For example, the second chemical liquid supply unit 138B supplies the second chemical liquid to the upper surface Wa of the substrate W. If one of the insulating layer N and the sacrificial layer Sa is selectively etched in the first etching, the other of the insulating layer N and the sacrificial layer Sa is selectively etched in the second etching. As described above, by performing two etches with different selectivity ratios, the amount of etching of the insulating layer N can be made equal to the amount of etching of the sacrificial layer Sa.

As described above with reference to Figures 2, 6 and 7, the processing liquid supply unit 132 supplies the processing liquid to the substrate W, thereby forming the filling layer F. When the processing liquid contains a solute and a volatile solvent, it is preferable to heat the processing liquid after the processing liquid supply unit 132 supplies the processing liquid to the substrate W. By heating the processing liquid, the filling layer F can be formed quickly.

Next, the semiconductor element forming method of this embodiment will be described with reference to Figures 11 and 12. Figure 11 is a schematic diagram of a substrate processing apparatus 100 of this embodiment. The substrate processing apparatus 100 of Figure 11 has a similar configuration to the substrate processing apparatus 100 shown in Figure 2, except that it further includes a heat medium supply unit 140, a gas supply unit 142, and a shielding member 150, and therefore duplicated descriptions will be omitted to avoid redundancy.

The substrate processing apparatus 100 further includes a heat medium supply unit 140, a gas supply unit 142, and a shielding member 150. The heat medium supply unit 140 supplies a heat medium to the substrate W. The gas supply unit 142 supplies a gas to the substrate W. The shielding member 150 shields the substrate W from the vertically upper side.

The processing liquid supply unit 132 supplies a processing liquid containing a solute and a volatile solvent. The filling layer F is formed from the solute component.

The heat medium supplied by the heat medium supply unit 140 may be either liquid or gas. For example, the heat medium is warm water. While or after the processing liquid supply unit 132 is supplying the processing liquid to the upper surface Wa of the substrate W, the heat medium supply unit 140 heats the substrate W held by the spin base 121 and the chuck member 122 from the rear surface Wb side of the substrate W to form a filling layer on the upper surface Wa of the substrate W.

While the substrate W is rotating, the heat medium supply unit 140 supplies the heat medium toward the center position of the rear surface Wb of the substrate W. The supplied heat medium spreads over substantially the entire rear surface Wb of the substrate W due to the action of centrifugal force. As a result, the processing liquid on the substrate W and the upper surface Wa of the substrate W is heated, and the solvent evaporates from the processing liquid, quickly forming a filling layer.

The heat medium supply unit 140 includes a pipe 140a, a valve 140b, and a nozzle 140n. The nozzle 140n faces the rear surface Wb of the substrate W. The nozzle 140n ejects the heat medium onto the rear surface Wb of the substrate W. The nozzle 140n is connected to the pipe 140a. The heat medium is supplied to the pipe 140a from a supply source. The valve 140b opens and closes the flow path in the pipe 140a.

The gas supply unit 142 supplies gas to the upper surface Wa of the substrate W. The gas supplied by the gas supply unit 142 preferably includes an inert gas. The inert gas includes nitrogen gas.

The gas supply unit 142 includes a pipe 142a and a valve 142b. Gas is supplied to the pipe 142a from a supply source. The valve 142b opens and closes the flow path in the pipe 142a.

The shielding member 150 is located above the substrate holding part 120. The shielding member 150 faces the substrate W. Here, the outer diameter of at least a portion of the shielding member 150 along the horizontal direction is approximately equal to the outer diameter of the substrate W.

The shielding member 150 moves relative to the substrate W between a close position and a retracted position. When the shielding member 150 is in the close position, it descends and approaches the upper surface of the substrate W at a predetermined distance. At the close position, the shielding member 150 covers the surface of the substrate W and shields the upper part of the substrate W. When the shielding member 150 is in the retracted position, it is located vertically above the close position. When the shielding member 150 changes from the close position to the retracted position, the shielding member 150 rises and moves away from the substrate W.

The shielding member 150 includes a shielding plate 152, a support shaft 154, and a nozzle 156. The support shaft 154 is located on the line of the rotation axis Ax of the shaft 123. The shielding plate 152 extends horizontally from the support shaft 154. Here, the shielding plate 152 has a shape that extends horizontally. For example, the shielding plate 152 is substantially disc-shaped.

The nozzle 156 is connected to the pipe 134a of the removal liquid supply unit 134 and the pipe 142a of the gas supply unit 142. The nozzle 156 functions as a nozzle for the removal liquid supply unit 134 and the gas supply unit 142.

The control unit 102 can control the valves 140b, 142b separately to switch the states of the valves 140b, 142b between an open state and a closed state. Specifically, the control unit 102 can control the valves 140b, 142b to open the valves 140b, 142b to allow the heat medium and gas flowing through the pipes 140a, 142a toward the nozzles 140n, 156 to pass. The control unit 102 can also control the valves 140b, 142b to close the valves 140b, 142b to stop the supply of the heat medium and gas flowing through the pipes 140a, 142a toward the nozzles 140n, 156.

The control unit 102 also controls the shielding member 150 to move the shielding member 150 relative to the substrate W between the approach position and the retracted position.

Figure 12 is a flow diagram of the semiconductor device formation method of this embodiment. The flow diagram of Figure 12 is similar to the flow diagram of Figure 8, except that the formation of the filling layer F is performed in multiple steps, and duplicated descriptions are omitted to avoid redundancy.

The formation of the filling layer F in step S12 includes supplying the treatment liquid in step S12a, spinning off in step S12b, and heating in step S12c.

In step S12a, the processing liquid is supplied. The processing liquid supply unit 132 supplies the processing liquid to the upper surface Wa of the substrate W. At this time, the rotation speed of the substrate W is 10 rpm to 100 rpm.

In step S12b, after supplying the processing liquid, the substrate holder 120 increases the rotation speed of the substrate W to spin off the processing liquid from the upper surface Wa of the substrate W. For example, the rotation speed of the substrate W is increased to 300 rpm to 1500 rpm.

In step S12c, the heat medium supplying unit 140 supplies a heat medium to the back surface Wb of the substrate W. For example, after the processing liquid is spun off, the rotation speed of the substrate W is reduced to 100 rpm to 1000 rpm. By heating the processing liquid on the top surface Wa of the substrate W, a filling layer F can be quickly formed from the processing liquid.

In the description with reference to Figures 11 and 12, the processing liquid is heated by the heat medium supplied from the heat medium supply unit 140, but this embodiment is not limited to this. A heat source such as a lamp or an electric heater may be installed in the substrate processing apparatus 100, and the processing liquid may be heated using heat from the heat source.

It is preferable to supply a stripping liquid to the substrate W before supplying the removal liquid for removing the filling layer F and/or the partial filling layer Fp.

Next, the semiconductor element forming method of this embodiment will be described with reference to Figures 6, 13, and 14. Figure 13 is a schematic diagram of a substrate processing apparatus 100 of this embodiment. The substrate processing apparatus 100 of Figure 13 has a similar configuration to the substrate processing apparatus 100 shown in Figure 11, except that the liquid supply unit 130 further includes a rinsing liquid supply unit 137 and a stripping liquid supply unit 160, and duplicated descriptions will be omitted to avoid redundancy.

In the substrate processing apparatus 100 of this embodiment, the liquid supply unit 130 further includes a rinsing liquid supply unit 137 and a stripping liquid supply unit 160. The rinsing liquid supply unit 137 supplies a rinsing liquid to the substrate W. The stripping liquid supply unit 160 supplies a stripping liquid to the substrate W.

The rinsing liquid supply unit 137 supplies rinsing liquid to the substrate W. The rinsing liquid supply unit 137 includes a pipe 137a and a valve 137b. The rinsing liquid is supplied to the pipe 137a from a supply source. The valve 137b opens and closes the flow path in the pipe 137a.

The nozzle 156 of the shielding member 150 is connected to the pipe 137a of the rinsing liquid supply unit 137. The nozzle 156 functions as a nozzle of the rinsing liquid supply unit 137.

The remover liquid supply unit 160 supplies a remover liquid to the upper surface Wa of the substrate W. The remover liquid has a remover property with respect to the filling layer F. By supplying the remover liquid, the filling layer F can be easily removed thereafter. For example, the remover liquid includes at least one of DIW and SC1. By controlling the concentration and processing time of the remover liquid supplied by the remover liquid supply unit 160, a partial filling layer Fp can be appropriately formed from the filling layer F.

Here, the stripping liquid supply unit 160 includes a first stripping liquid supply unit 162 and a second stripping liquid supply unit 164. The first stripping liquid supply unit 162 supplies a first stripping liquid to the upper surface Wa of the substrate W. The second stripping liquid supply unit 164 supplies a second stripping liquid to the upper surface Wa of the substrate W. The first stripping liquid supply unit 162 supplies a stripping liquid different from the second stripping liquid supply unit 164 to the upper surface Wa of the substrate W.

The first stripping liquid supply unit 162 includes a pipe 162a and a valve 162b. The first stripping liquid is supplied from a supply source to the pipe 162a. The valve 162b opens and closes the flow path in the pipe 162a.

The second stripping liquid supply unit 164 includes a pipe 164a and a valve 164b. The second stripping liquid is supplied from a supply source to the pipe 164a. The valve 164b opens and closes the flow path in the pipe 164a.

The stripping liquid supply unit 160 further includes a pipe 160a and a nozzle 160n. The pipe 160a is connected to the pipe 162a and the pipe 164a. The nozzle 160n ejects the stripping liquid onto the upper surface Wa of the substrate W. The nozzle 160n is connected to the pipe 160a. It is preferable that the nozzle 160n is configured to be movable relative to the substrate W.

The control unit 102 can separately control the valves 162b and 164b of the stripping liquid supply unit 160 to switch the states of the valves 162b and 164b between an open state and a closed state. Specifically, the control unit 102 can control the valves 162b and 164b of the stripping liquid supply unit 160 to open the valves 162b or 164b to pass the first stripping liquid and the second stripping liquid flowing through the pipes 160a and 162a or 164a toward the nozzle 160n. The control unit 102 can also control the valves 162b and 164b of the stripping liquid supply unit 160 to close the valves 162b and 164b to stop the supply of the first stripping liquid and the second stripping liquid flowing through the pipes 160a and 162a or 164a toward the nozzle 160n.

When the processing liquid contains a heat-sensitive water-soluble resin as a solute, in order to make the temperature of the heat-sensitive water-soluble resin lower than the deterioration temperature when the processing liquid is heated, it is preferable to use a heat medium whose boiling point is lower than the deterioration temperature. For example, in the case of a heat-sensitive water-soluble resin whose deterioration temperature is 180°C, DIW (boiling point: 100°C) or the like can be used as the heat medium. It is more preferable that the temperature of the heat medium is lower than the boiling point of the solvent. By making the temperature of the processing liquid lower than the boiling point of the solvent, the solvent can be left in the filling layer. Then, the interaction between the solvent remaining in the filling layer and the stripping liquid makes it easier to strip the filling layer from the upper surface of the substrate W.

Figure 14 is a flow diagram of the semiconductor device formation method of this embodiment. The flow diagram of Figure 14 is similar to the flow diagram of Figure 12, except that a remover is supplied to remove the filling layer and partial filling layer, and a stripper is supplied before the removal liquid is supplied, and duplicate descriptions are omitted to avoid redundancy.

After the substrate W is heated in step S12c, a first stripping liquid is supplied in step S13a. The first stripping liquid supply unit 162 supplies the first stripping liquid to the substrate W. For example, the first stripping liquid supply unit 162 supplies DIW as the first stripping liquid.

In step S13b, a second stripping liquid is supplied. The second stripping liquid supply unit 164 supplies the second stripping liquid to the substrate W. For example, the second stripping liquid supply unit 164 supplies SC1 as the second stripping liquid.

In step S13c, a rinse liquid is supplied. For example, the rinse liquid supply unit 137 supplies the rinse liquid to the upper surface Wa of the substrate W.

Then, in step S14a, the filling layer F is partially dissolved by the removal liquid to form a partial filling layer Fp. The removal liquid supply unit 134 supplies the removal liquid to the substrate W for a predetermined period of time. The removal liquid Ds is applied to the filling layer F in the recess R, thereby partially dissolving the filling layer F to form a partial filling layer Fp in the recess R. By controlling the concentrations and processing times of the first remover liquid, the second remover liquid, and the removal liquid supplied by the first remover liquid supply unit 162, the second remover liquid supply unit 164, and the remover liquid supply unit 134, the partial filling layer Fp can be appropriately formed from the filling layer F.

After the water repellent is applied in step S16, a remover is applied in step S18a to remove the water repellent P and the partial filling layer Fp, except for the coating layer Ps. The subsequent processing is similar.

In the flow diagram shown in FIG. 14, the first and second remover liquids are supplied before the filling layer F is partially dissolved with the removal liquid, but this embodiment is not limited to this. The first and second remover liquids may be supplied not only before the filling layer F is partially dissolved, but also before the partial filling layer Fp is dissolved. Alternatively, the first and second remover liquids may be supplied not only before the filling layer F is partially dissolved, but also before the partial filling layer Fp is dissolved.

In the flow diagram shown in FIG. 14, the first and second stripping liquids are supplied, but this embodiment is not limited to this. Only one of the first and second stripping liquids may be supplied before dissolving the filling layer F and/or the partial filling layer Fp.

In the above description with reference to Figures 13 and 14, the filling layer F and/or the partial filling layer Fp are removed by a stripping liquid and a removing liquid, but this embodiment is not limited to this. The filling layer F and/or the partial filling layer Fp may be removed by heating.

Next, the semiconductor element forming method of this embodiment will be described with reference to Figures 6, 15, and 16. Figure 15 is a schematic diagram of a substrate processing apparatus 100 of this embodiment. The substrate processing apparatus 100 of Figure 15 has a similar configuration to the substrate processing apparatus 100 shown in Figure 11, except that the processing liquid contains a sublimable substance and the filling layer formed from the processing liquid is cooled, and therefore, to avoid redundancy, duplicate descriptions will be omitted.

In this embodiment, the processing liquid supply unit 132 supplies a processing liquid containing a sublimable substance to the upper surface Wa of the substrate W. Furthermore, when mixing a sublimable substance in a molten state, a solvent that is compatible with the sublimable substance in a molten state is preferable. Furthermore, when dissolving a sublimable substance as a solute, a solvent that is soluble in the sublimable substance is preferable.

The substrate processing apparatus 100 further includes a coolant supply unit 144. The coolant supply unit 144 supplies a coolant that is lower than room temperature to the substrate W. The coolant is, for example, DIW that is cooled below room temperature.

The coolant supplied by the coolant supply unit 144 may be either liquid or gas. After the processing liquid supply unit 132 supplies the processing liquid to the upper surface Wa of the substrate W, the coolant supply unit 144 cools the substrate W held by the spin base 121 and the chuck member 122 from the rear surface Wb side of the substrate W.

While the substrate W is rotating, the coolant supply unit 144 supplies coolant toward the center position of the back surface Wb of the substrate W. The supplied coolant spreads over almost the entire back surface Wb of the substrate W due to the action of centrifugal force. This causes the processing liquid on the substrate W and the upper surface Wa of the substrate W to cool and solidify, allowing a filling layer to be quickly formed from the processing liquid.

The refrigerant supply unit 144 includes a pipe 144a and a valve 144b. A refrigerant is supplied to the pipe 144a from a supply source. The valve 144b opens and closes the flow path in the pipe 144a. The pipe 144a is connected to the pipe 140a of the heat medium supply unit 140. The refrigerant is supplied to the back surface Wb of the substrate W from a nozzle 140n of the heat medium supply unit 140.

The substrate processing apparatus 100 is equipped with a heat medium supplying unit 140 in addition to the coolant supplying unit 144. The heat medium supplying unit 140 supplies heat medium to the rear surface Wb of the substrate W until just before the coolant supplying unit 144 supplies coolant to the rear surface Wb of the substrate W, thereby forming a thin filling layer F. This reduces the internal stress generated in the filling layer F.

Figure 16 is a flow diagram of the semiconductor device formation method of this embodiment. The flow diagram of Figure 16 is similar to the flow diagram of Figure 8, except that the treatment liquid contains a sublimable substance and is heated when removing the partial filling layer, and duplicated descriptions are omitted to avoid redundancy.

In step S12, a filling layer F is formed. The processing liquid supply unit 132 supplies a processing liquid to the substrate W. Here, the processing liquid contains a sublimable substance. The processing liquid supply unit 132 supplies the processing liquid containing the sublimable substance to the upper surface Wa of the substrate W.

When forming the filling layer F, the coolant supply unit 144 supplies the coolant to the rear surface Wb of the substrate W. This causes the processing liquid to solidify and form the filling layer F. The coolant supplied to the rear surface Wb of the substrate W spreads over substantially the entire rear surface Wb of the substrate W due to the action of centrifugal force. This starts cooling the processing liquid on the upper surface Wa of the substrate W.

When removing the partial filling layer Fp in step S18b, the supply of refrigerant by the refrigerant supply unit 144 is stopped, and the supply of heat medium by the heat medium supply unit 140 is started. This causes the partial filling layer Fp to sublimate, so that the partial filling layer Fp can be removed.

Next, the semiconductor device forming method of this embodiment will be described with reference to Figures 17 and 18. Figure 17 is a schematic diagram of a substrate processing apparatus 100 of this embodiment. The substrate processing apparatus 100 of Figure 17 has a similar configuration to the substrate processing apparatus 100 shown in Figure 2, except that it further includes an aqueous solution supply unit 200 and a heating mechanism 210, and therefore duplicated descriptions will be omitted to avoid redundancy.

The aqueous solution supply unit 200 supplies the aqueous solution to the upper surface Wa of the substrate W. The supplied aqueous solution comes into contact with the surface of the formed filling layer.

As the aqueous solution, an acidic aqueous solution can be used. The acidic aqueous solution contains, for example, acetic acid, formic acid, hydroxyacetic acid, or sulfonic acid.

The aqueous solution supply unit 200 includes a pipe 200a, a valve 200b, and a nozzle 200n. The nozzle 200n ejects the aqueous solution onto the upper surface Wa of the substrate W. The nozzle 200n is connected to the pipe 200a. The aqueous solution is supplied to the pipe 200a from a supply source. The valve 200b opens and closes a flow path in the pipe 200a. It is preferable that the nozzle 200n is configured to be movable relative to the substrate W.

The substrate processing apparatus 100 further includes a heating mechanism 210. The heating mechanism 210 heats the substrate W. The heating mechanism 210 heats the substrate W when the recess R of the substrate W is filled with the filling layer F. Here, the heating mechanism 210 is disposed above the spin base 121.

The heating mechanism 210 can increase or decrease the energy applied to the substrate W by increasing or decreasing the power supplied to the heating mechanism 210. The amount of heat applied to the substrate W increases or decreases correspondingly to the increase or decrease in energy. The heating mechanism 210 is a circular plate, and the diameter of the heating mechanism 210 is larger than the radius of the substrate W. Furthermore, when the heating mechanism 210 is used together with the shielding member 150, the diameter of the heating mechanism 210 may be smaller than the radius of the shielding plate 152 (Figure 15). This shape allows the heating mechanism 210 to heat the entire substrate W uniformly.

The heating mechanism 210 has a heating section. For example, the heating section heats the filling layer with light or heat. The heating section may be a heater, a lamp, or an LED, and is not limited to these as long as it has a heating function. The heating sections may be uniformly arranged in a concentric or lattice pattern on the heating mechanism 210. With this arrangement, the heating mechanism 210 can uniformly heat the entire substrate W. Furthermore, the heating mechanism 210 may heat the substrate W surface differently depending on the region. For example, the heating mechanism 210 can separate the substrate W into a central portion, a middle portion, and an outer periphery in three concentric circles, and heat the central portion, the middle portion, and the outer periphery to different temperatures. Note that the regions on the substrate W that are separated as different temperature regions are not limited to concentric circles, and may be changed as appropriate.

While or after the processing liquid supply unit 132 supplies processing liquid to the upper surface Wa of the substrate W, the heating mechanism 210 heats the substrate W held by the spin base 121 and the chuck member 122 from the rear surface Wb side of the substrate W to form a filling layer on the upper surface Wa of the substrate W. The heating mechanism 210 has a lifting mechanism (not shown) and is vertically spaced downward from the substrate W, and moves up and down between a standby position where the lifting mechanism waits, a contact position where it contacts the substrate W, and an approach position between the standby position and the contact position.

In addition, while or after the aqueous solution supply unit 200 is supplying the aqueous solution to the upper surface Wa of the substrate W, the heating mechanism 210 heats the substrate W held by the spin base 121 and the chuck member 122 from the rear surface Wb side of the substrate W to dissolve or modify a part of the filling layer F on the upper surface Wa of the substrate W. This may form a partial filling layer Fp on the upper surface Wa of the substrate W. The heating mechanism 210 has a lifting mechanism (not shown) and is vertically spaced downward from the substrate W, and lifts and lowers between a standby position where the lifting mechanism waits, a contact position where it contacts the substrate W, and an approach position between the standby position and the contact position.

Note that here, the heating mechanism 210 heats the substrate W from the back surface Wb side of the substrate W, but the heating mechanism 210 may also heat the substrate W from the top surface Wa side of the substrate W. In this case, the heating mechanism 210 moves vertically upward away from the substrate W and moves up and down between a standby position where the lifting mechanism waits, a contact position where it contacts the substrate W, and an approach position between the standby position and the contact position.

When the substrate W is rotating, the heating mechanism 210 is moved from the standby position to the contact position by the lifting mechanism. The heating mechanism 210 may also be stationary between the standby position and the contact position. Even if the heating mechanism 210 does not move from the standby position, the output of the heating mechanism 210 may be increased to increase the amount of heat.

Figure 18 is a flow diagram of the semiconductor device forming method of this embodiment. The flow diagram of Figure 18 is similar to the flow diagram of Figure 8, except that an aqueous solution is supplied to remove a portion of the filling layer, and heating is performed after the aqueous solution is supplied, and duplicated descriptions are omitted to avoid redundancy.

In step S14, a portion of the filling layer F is removed. An aqueous solution is supplied to the filling layer F, the filling layer F in contact with the aqueous solution is heated, and then a removal liquid is applied to the filling layer F in the recess R, thereby partially dissolving the filling layer F and forming a partial filling layer Fp in the recess R. The partial removal of the filling layer F in step S14 includes supplying the aqueous solution in step S14b, heating in step S14c, and supplying the removal liquid in step S14d.

In step S14b, the aqueous solution supply unit 200 supplies the aqueous solution to the substrate W for a predetermined period of time. The aqueous solution comes into contact with the filling layer F in the recess R, and penetrates or permeates into the filling layer F.

In step S14c, the substrate W is heated for a predetermined period of time by the heating mechanism 210. The heating diffuses the acid contained in the filling layer F, and the part of the filling layer F into which the acid has diffused is partially dissolved and/or denatured. At this time, a partial filling layer Fp may be formed in the recess R. By controlling the heating time and heating temperature by the heating mechanism 210, and the distance between the heating mechanism 210 and the substrate W, it is possible to control the area of the filling layer F that is removed from the filling layer F, and it is possible to appropriately form a partial filling layer Fp by partially removing the part of the filling layer F located on the surface side of the filling layer F.

In step S14d, the removing liquid supply unit 134 supplies the removing liquid to the substrate W for a predetermined period of time. The removing liquid is applied to the region of the filling layer F where the acid has diffused, thereby partially dissolving the filling layer F and forming a partial filling layer Fp in the recess R.

The removal liquid for partially removing the portion of the filling layer F located on the surface side of the filling layer F may be the same as or different from the removal liquid for the partial filling layer Fp.

17 and 18, the substrate W during or after the aqueous solution is supplied is heated by a heating mechanism such as a lamp or an electric heater, but this embodiment is not limited to this. A heat medium supplying unit may be provided as a heating mechanism in the substrate processing apparatus 100, and the substrate W during or after the aqueous solution is supplied may be heated by using a heat medium supplied from the heat medium supplying unit. The heat medium is, for example, heated high-temperature nitrogen ( _N2 ) gas.

In the above description with reference to Figures 1 to 18, the substrate processing apparatus 100 is of a single-wafer type, and the substrate processing apparatus 100 processes the substrates W one by one, but the present invention is not limited to this. The substrate processing apparatus may be of a batch type.

Next, the substrate processing apparatus 100 of this embodiment will be described with reference to FIG. 19. FIG. 19 is a schematic diagram of the substrate processing apparatus 100. The substrate processing apparatus 100 can process multiple substrates W at once.

The substrate processing apparatus 100 includes a substrate holding unit 120 and a liquid supply unit 130. The liquid supply unit 130 includes a processing liquid supply unit 132, a removal liquid supply unit 134, a water repellent supply unit 136, and a chemical liquid supply unit 138. The processing liquid supply unit 132, the removal liquid supply unit 134, the water repellent supply unit 136, and the chemical liquid supply unit 138 each store liquid.

The treatment liquid supply unit 132 includes a treatment liquid storage tank 132t. A treatment liquid is stored in the treatment liquid storage tank 132t. A filling layer is formed from the treatment liquid. For example, the treatment liquid includes a solute and a volatile solvent. Alternatively, the treatment liquid includes a sublimable substance.

The removal liquid supply unit 134 includes a removal liquid storage tank 134t. The removal liquid storage tank 134t stores the removal liquid. The removal liquid can remove the filling layer formed from the processing liquid. By controlling the time for which the removal liquid is supplied, the filling layer can be selectively removed from the substrate W.

As the removal liquid, any solvent that dissolves any of the resins can be used. As the removal liquid, for example, organic solvents such as thinner, toluene, acetate esters, alcohols, and glycols, and acidic liquids such as acetic acid, formic acid, and hydroxyacetic acid can be used.

The water repellent supply unit 136 includes a water repellent storage tank 136t. A liquid water repellent is stored in the water repellent storage tank 136t. A water repellent layer is formed on the substrate W by the water repellent. The water repellent is a water repellent that hydrophobicizes silicon (Si) itself and compounds containing silicon. The water repellent is, for example, a silane coupling agent. The silane coupling agent includes, for example, at least one of HMDS (hexamethyldisilazane), TMS (tetramethylsilane), fluorinated alkylchlorosilane, alkyldisilazane, and non-chloro water repellent. The non-chloro water repellent includes, for example, at least one of dimethylsilyldimethylamine, dimethylsilyldiethylamine, hexamethyldisilazane, tetramethyldisilazane, bis(dimethylamino)dimethylsilane, N,N-dimethylaminotrimethylsilane, N-(trimethylsilyl)dimethylamine, and an organosilane compound.

The chemical supply unit 138 includes a chemical storage tank 138t. A chemical is stored in the chemical storage tank 138t. The chemical can be processed by chemical processing using the chemical. By chemical processing, the substrate W can be subjected to any one of etching, surface treatment, imparting properties, forming a processed film, and removing at least a portion of a film. Typically, the chemical is an etching solution used in etching the substrate W.

The chemical solution contains hydrofluoric acid. For example, the hydrofluoric acid may be heated to 40°C or higher and 70°C or lower, or to 50°C or higher and 60°C or lower. However, the hydrofluoric acid does not have to be heated. The chemical solution may also contain water or phosphoric acid.

The chemical solution may further contain hydrogen peroxide. The chemical solution may also contain SC1 (ammonia hydrogen peroxide mixture), SC2 (hydrochloric acid hydrogen peroxide mixture), or aqua regia (a mixture of concentrated hydrochloric acid and concentrated nitric acid).

The substrate holding unit 120 holds a substrate W. The normal direction of the main surface of the substrate W held by the substrate holding unit 120 is parallel to the Y direction. The substrate holding unit 120 moves the substrates W while holding multiple substrates W. For example, the substrate holding unit 120 moves vertically upward or vertically downward while holding the substrates W. Alternatively, the substrate holding unit 120 may move horizontally while holding the substrates W.

The substrate holding unit 120 includes a main body plate 122b and a holding rod 124b. The main body plate 122b is a plate extending in the vertical direction (Z direction). The holding rod 124b extends in the horizontal direction (Y direction) from one main surface of the main body plate 122b. Here, two holding rods 124b extend in the Y direction from one main surface of the main body plate 122b. The multiple substrates W are arranged in the forward and backward directions of the paper, and are held in an upright position (vertical position) by the lower edge of each substrate W being abutted by the multiple holding rods 124b.

The substrate processing apparatus 100 further includes a control device 101. The control device 101 includes a control unit 102 and a memory unit 104. The control unit 102 controls the substrate holding unit 120.

In the substrate processing apparatus 100 of this embodiment, the control unit 102 can adjust the diameter of the recess provided in the stacked structure L of the substrate W by treating the substrate W held by the substrate holder 120 with different liquids, in the same manner as in the single-wafer processing, as described with reference to Figures 6 to 16 for the single-wafer processing.

In the description with reference to Figures 1 to 19, the memory element Se is disposed in the recess R of the substrate W, but this embodiment is not limited to this. A dummy memory element that has a similar configuration to the memory element Se but is not used as a memory element may be formed in the recess R of the substrate W. Alternatively, a contact plug for electrically connecting to the memory element Se may be formed in the recess R of the substrate W.

Next, a semiconductor element 300 formed by the semiconductor element forming method of this embodiment will be described with reference to FIG. 20. FIG. 20 is a schematic diagram of the semiconductor element 300.

The semiconductor element 300 has a plurality of recesses R. The plurality of recesses R includes a memory recess Rs in which the memory element Se is arranged, as well as a contact recess Rc in which the contact plug Cp is arranged. The contact recess Rc is electrically connected to the conductive layer M.

According to the semiconductor element forming method of this embodiment, the diameter of not only the memory recess Rs but also the contact recess Rc can be made uniform from the surface portion to the deep portion. Therefore, the strength with which the contact recess Rc supports the semiconductor element can be made uniform.

The above describes the embodiments of the present invention with reference to the drawings. However, the present invention is not limited to the above embodiments, and can be implemented in various aspects without departing from the gist of the present invention. In addition, various inventions can be formed by appropriately combining multiple components disclosed in the above embodiments. For example, some components may be deleted from all components shown in the embodiments. Furthermore, components from different embodiments may be appropriately combined. The drawings are mainly shown schematically for ease of understanding, and the thickness, length, number, spacing, etc. of each component shown in the drawings may differ from the actual ones due to the convenience of drawing. In addition, the material, shape, dimensions, etc. of each component shown in the above embodiments are only examples and are not particularly limited, and various changes are possible within a range that does not substantially deviate from the effects of the present invention.

The present invention is suitable for use in semiconductor element forming methods and substrate processing apparatus.

REFERENCE SIGNS LIST 100 Substrate processing apparatus 110 Chamber 120 Substrate holder 130 Liquid supply section 132 Processing liquid supply section 134 Removal liquid supply section 136 Water repellent agent supply section 138 Chemical liquid supply section W Substrate

Claims (14)

forming a coating layer that selectively covers a portion of a recess located on a surface side of the recess provided in a laminate structure supported by a substrate;
and etching the deep portion of the recess with a chemical solution so as to increase the diameter of the portion of the recess deeper than the coating layer.
The step of forming the coating layer includes:
forming a filling layer to fill the recess;
a step of forming the filling layer, and then heating the filling layer while the filling layer is in contact with an aqueous solution to partially remove a portion of the filling layer located on a surface side thereof, thereby forming a partial filling layer that partially fills a deep portion of the recess;
supplying a water repellent agent after forming the partial filling layer;
and removing the partial filling layer and the water repellent after supplying the water repellent to form the covering layer on the front surface side of the recess. The method for forming a semiconductor device according to claim 1, wherein the step of removing the partial filling layer includes a step of dissolving the partial filling layer by supplying a removal liquid. The method for forming a semiconductor device according to claim 2, wherein the step of partially removing the filling layer includes a step of supplying a removal liquid that removes the filling layer. The method for forming a semiconductor device according to any one of claims 1 to 3, wherein in the etching step, the chemical solution contains any one of hydrofluoric acid, water, and phosphoric acid. The semiconductor element forming method according to any one of claims 1 to 4, wherein a plurality of memory elements are formed in the recess. The laminated structure has a plurality of recesses as the recess,
6. The method of claim 1, wherein a difference in top diameter between the recesses is 5% or less. The method for forming a semiconductor device according to claim 1 , further comprising the step of: providing an etching stop layer between the substrate and the laminated structure. 8. The method for forming a semiconductor device according to claim 1 , wherein an acidic aqueous solution is supplied as the aqueous solution in the step of forming the partial filling layer. a processing liquid supply unit that supplies a processing liquid;
a water repellent supply unit that supplies a water repellent;
A chemical supply unit that supplies a chemical;
an aqueous solution supply unit for supplying an aqueous solution;
a heating mechanism for heating the packed bed formed from the treatment liquid;
a control unit that controls the treatment liquid supply unit, the water repellent agent supply unit, the chemical liquid supply unit, the aqueous solution supply unit, and the heating mechanism,
The control unit is
(1) supplying the treatment liquid to form a filling layer that fills a recess provided in a laminate structure supported by a substrate;
(2) After the filling layer is formed, the filling layer is heated by the heating mechanism while being in contact with the aqueous solution supplied from the aqueous solution supply unit, thereby partially removing a portion of the filling layer located on the surface side, and forming a partial filling layer that partially fills a deep portion of the recess;
(3) supplying the water repellent to form a coating layer that selectively covers a portion of the recess that is located on the surface side and is not covered by the partial filling layer;
(4) Supplying the chemical solution to increase the diameter of a portion of the recess deeper than the coating layer;
the processing liquid supply unit, the water repellent agent supply unit, the chemical liquid supply unit, the aqueous solution supply unit, and the heating mechanism are controlled in such a manner as described above. The substrate processing apparatus according to claim 9 , wherein the heating mechanism heats the filling layer with heat or light. The substrate processing apparatus according to claim 9 , wherein the heating mechanism includes a heater. The substrate processing apparatus according to claim 9 , wherein the heating mechanism includes a lamp. The heating mechanism includes a heat medium supply unit that supplies a heat medium,
The substrate processing apparatus according to claim 9 , wherein the heat medium includes heated nitrogen gas. The substrate processing apparatus according to claim 9 , wherein the aqueous solution supply unit supplies an acidic aqueous solution as the aqueous solution.

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