JP7609671B2 - SUBSTRATE PROCESSING METHOD AND SUBSTRATE PROCESSING APPARATUS - Google Patents

Description

The present invention relates to a substrate processing method for processing a substrate, and a substrate processing apparatus for processing a substrate.
Substrates to be processed include, for example, semiconductor wafers, substrates for FPDs (Flat Panel Displays) such as liquid crystal displays and organic EL (Electroluminescence) displays, substrates for optical disks, substrates for magnetic disks, substrates for magneto-optical disks, substrates for photomasks, ceramic substrates, substrates for solar cells, and the like.

With the increase in bit density, there is a demand for forming memory holes with a high aspect ratio. When forming a memory hole with a high aspect ratio in a processing target layer by dry etching, the processing target layer may not be sufficiently etched at the bottom side of the memory hole, and the shape of the memory hole may become tapered from the opening to the bottom.
Therefore, Patent Document 1 listed below proposes a technique for forming a memory hole having a straight sidewall by using a mask layer having a grating structure in which amorphous silicon layers and spaces are alternately arranged (stacked).

JP 2020-155612 A

In the technology disclosed in Patent Document 1, memory holes having a highly uniform width are formed by dry etching. However, in order to make the width of recesses such as memory holes more uniform, there is a demand for a technology for further etching a substrate in which recesses are already formed, thereby improving the uniformity of the width of the recesses.
Therefore, one object of the present invention is to provide a substrate processing method and a substrate processing apparatus that can improve the uniformity of the width of a recess in the depth direction of the recess provided in the main surface of a substrate.

One embodiment of the present invention provides a substrate processing method for processing a substrate having a first main surface and a second main surface opposite to the first main surface. The substrate processing method includes an etching processing liquid supplying step of supplying an etching processing liquid containing an etching component and a gelling agent to the first main surface, a cooling step of cooling the second main surface to a temperature below the freezing point of the gelling agent after the etching processing liquid supplying step, a rinsing liquid supplying step of supplying a rinsing liquid having a temperature above the melting point of the gelling agent to the first main surface while continuing to cool the second main surface, and a cooling stopping step of stopping the cooling of the second main surface after the rinsing liquid supplying step.

According to this substrate processing method, an etching treatment liquid is supplied to a first main surface of a substrate. When a substrate having a recess formed on its first main surface is used, the etching treatment liquid supplied to the first main surface enters the recess. After the etching treatment liquid is supplied to the first main surface of the substrate, the second main surface is cooled to a temperature below the freezing point of the gelling agent. As a result, the temperature of the substrate reaches a temperature below the freezing point of the gelling agent, and the etching treatment liquid on the first main surface turns into a gel. Therefore, a gel is also formed in the recess.

Then, a rinse liquid having a temperature equal to or higher than the melting point of the gelling agent is supplied to the first main surface, so that the opening side portion of the gel located at the opening of the recess is transformed into an etching treatment liquid, and the etching treatment liquid formed by the solation of the opening side portion is replaced by the rinse liquid and removed from the recess.
The bottom portion of the gel formed in the recess, which is closer to the bottom than the opening portion, is closer to the second main surface than the opening portion and is therefore more susceptible to the cooling of the second main surface. Therefore, by continuing to cool the second main surface while supplying the rinsing liquid to the first main surface, the bottom portion can be maintained in a gel state, even though the rinsing liquid having a temperature equal to or higher than the melting point of the gelling agent is supplied to the upper surface of the substrate W.

After the supply of the rinsing liquid to the first main surface is stopped, the cooling to the second main surface is stopped. This causes the temperature of the gel remaining in the recess to rise, and the gel remaining in the recess is transformed into an etching liquid. The etching components diffuse into the rinsing liquid that comes into contact with the etching liquid. This creates a concentration gradient of the etching components in the recess such that the concentration of the etching components decreases from the bottom of the recess toward the opening. Therefore, an etching rate gradient occurs from the opening of the recess toward the bottom. This causes the width of the recess on the bottom side to increase so that the recess approaches a straight shape. As a result, the uniformity of the width of the recess in the depth direction of the recess provided on the first main surface of the substrate can be improved.

In one embodiment of the present invention, the cooling stopping step includes a heating step of heating the second main surface to a temperature equal to or higher than the melting point.
Therefore, after the supply of the rinsing liquid to the first main surface is stopped, the temperature of the gel remaining in the recesses can be quickly increased to convert the gel remaining in the recesses into an etching treatment liquid, thereby allowing etching of the substrate to begin quickly.

In one embodiment of the present invention, the heating step includes a step of heating the substrate from the second main surface side by supplying a heating fluid having a temperature equal to or higher than the melting point to the second main surface.
According to this method, the substrate can be heated from the second main surface side, that is, the second main surface can be heated, by the simple technique of supplying a heating fluid.

In one embodiment of the present invention, the heating step includes a step of heating the substrate from the second main surface side by a hot plate facing the second main surface from below and having a temperature equal to or higher than the melting point.
According to this method, by heating the substrate from the second main surface side with a hot plate, the second main surface can be heated with high uniformity over its entire area.

In one embodiment of the present invention, the cooling step includes a step of cooling the substrate from the second main surface side by supplying a cooling fluid having a temperature equal to or lower than the freezing point to the second main surface.
According to this method, the substrate can be cooled from the second main surface side, that is, the second main surface can be cooled, by the simple technique of supplying a cooling fluid.

In one embodiment of the present invention, the cooling step includes a step of cooling the substrate from the second main surface side by a cooling plate facing the second main surface from below and having a temperature equal to or lower than the freezing point.
According to this method, by cooling the substrate from the second main surface side by the cooling plate, the second main surface can be cooled with high uniformity over its entire area.

In one embodiment of the present invention, the depth of the recess is 0.5 μm or more and 1.5 μm or less, and the aspect ratio of the recess is 20 or more and 100 or less. A recess having such dimensions may have a tapered shape that narrows from the opening toward the bottom. Therefore, by performing the above-mentioned substrate processing using a substrate having a first main surface on which a recess having such dimensions is formed, it is possible to improve the uniformity of the width of the recess in the depth direction of the recess provided in the first main surface of the substrate.

In a preferred embodiment of the present invention, the substrate processing method further includes a supply resumption step of resuming supply of the rinsing liquid after the cooling stopping step.
According to this method, after the cooling stopping step, the supply of the rinse liquid to the first main surface of the substrate is resumed. More specifically, after the cooling of the substrate is stopped, the temperature of the gel remaining in the recess is increased, and the gel remaining in the recess is changed into an etching treatment liquid, the supply of the rinse liquid to the first main surface of the substrate is resumed. Therefore, etching by the etching components in the etching treatment liquid proceeds in a state in which the etching components in the etching treatment liquid are diffused in the recess, and after the width of the recess on the bottom side is appropriately widened, the etching treatment liquid in the recess can be removed from the recess by the rinse liquid. As a result, the uniformity of the width of the recess in the depth direction of the recess provided on the first main surface of the substrate can be improved.

In a preferred embodiment of the present invention, the substrate processing method further includes an auxiliary heating step of heating the substrate from the second main surface side while the rinsing liquid is being supplied to the substrate in the supply resuming step.
According to this method, when the rinsing liquid is supplied to the first main surface to remove the etching liquid in the recesses, the substrate is heated from the second main surface side. Therefore, it is possible to prevent the temperature of the etching liquid in the recesses from decreasing during the supply of the rinsing liquid. Therefore, it is possible to prevent the etching liquid from turning into a gel in the recesses and the etching components from remaining in the recesses.

In one embodiment of the present invention, the substrate processing method further includes a dry etching step of performing a dry etching process on the first main surface of the substrate before the etching solution supply step, so that even when a substrate having no recesses formed on its first main surface is used, the recesses can be formed on the first main surface.
Another embodiment of the present invention provides a substrate processing apparatus for processing a substrate having a first main surface and a second main surface opposite to the first main surface, the substrate processing apparatus including an etching processing liquid supplying member for supplying an etching processing liquid containing an etching component and a gelling agent to the first main surface, a cooling member for cooling the second main surface to a temperature equal to or lower than the freezing point of the gelling agent, and a rinsing liquid supplying member for supplying a rinsing liquid having a temperature equal to or higher than the melting point of the gelling agent to the first main surface.

According to this substrate processing apparatus, an etching treatment liquid is supplied to the first main surface of the substrate from an etching treatment liquid supply member. When a substrate having a recess formed on its first main surface is used, the etching treatment liquid supplied to the first main surface enters the recess. When the second main surface of the substrate with the etching treatment liquid adhering to its first main surface is cooled to a temperature below the freezing point of the gelling agent, the temperature of the substrate reaches a temperature below the freezing point of the gelling agent, and the etching treatment liquid on the first main surface turns into a gel. Thus, a gel is also formed in the recess.

Then, while continuing to cool the substrate, a rinse liquid having a temperature equal to or higher than the melting point of the gelling agent is supplied from the rinse liquid supply member to the first main surface, whereby the opening side portion of the gel located at the opening of the recess is transformed into an etching treatment liquid, and therefore the etching treatment liquid formed by the solation of the opening side portion can be removed from the recess by the rinse liquid.
The bottom side portion of the gel formed in the recess, which is closer to the bottom than the opening side portion, is closer to the second main surface than the opening side portion and is therefore more susceptible to the cooling of the second main surface. Therefore, by continuing to cool the second main surface while supplying the rinsing liquid to the first main surface, the bottom side portion can be maintained in a gel state even though the rinsing liquid having a temperature equal to or higher than the melting point of the gelling agent is supplied to the upper surface of the substrate W.

When the supply of the rinsing liquid to the first main surface is stopped and the cooling to the second main surface is stopped, the temperature of the gel remaining in the recess rises and the gel remaining in the recess changes to an etching treatment liquid. The etching components diffuse into the rinsing liquid that comes into contact with the etching treatment liquid. This creates a concentration gradient of the etching components in the recess such that the concentration of the etching components decreases from the bottom of the recess toward the opening. Therefore, an etching rate gradient occurs from the opening of the recess toward the bottom. This causes the width of the recess on the bottom side to increase so that the recess approaches a straight shape. As a result, the uniformity of the width of the recess in the depth direction of the recess provided on the first main surface of the substrate can be improved.

In another embodiment of the present invention, the substrate processing apparatus further includes a heating member that heats the second main surface to a temperature equal to or higher than the melting point. Therefore, by heating the second main surface to a temperature equal to or higher than the melting point of the gelling agent after the supply of the rinsing liquid to the first main surface has stopped, the temperature of the gel remaining in the recess can be quickly increased, and the gel remaining in the recess can be converted into an etching processing liquid. Therefore, etching of the substrate can be started promptly.

In another embodiment of the present invention, the depth of the recess is 0.5 μm or more and 1.5 μm or less, and the aspect ratio of the recess is 20 or more and 100 or less. A recess having such dimensions may have a tapered shape tapering from the opening side toward the bottom side. Therefore, by performing the above-mentioned substrate processing using a substrate having a first main surface on which a recess having such dimensions is formed, the uniformity of the width of the recess in the depth direction of the recess provided on the first main surface of the substrate can be improved.

In another embodiment of the present invention, the substrate processing apparatus further includes a dry processing unit that performs a dry etching process on the first main surface of the substrate. Therefore, even when a substrate is used that does not have a recess formed on its first main surface, a recess can be formed on the first main surface.

FIG. 1 is a schematic cross-sectional view for explaining the structure of a substrate to be processed. FIG. 2A is a plan view for explaining the configuration of the substrate processing apparatus according to the first embodiment of the present invention. FIG. 2B is an elevational view for explaining the configuration of the substrate processing apparatus. FIG. 3 is a cross-sectional view for explaining an example of the configuration of a wet processing unit provided in the substrate processing apparatus. FIG. 4 is a block diagram for explaining an example of a configuration relating to control of the substrate processing apparatus. FIG. 5 is a flow chart for explaining an example of a substrate processing performed by the substrate processing apparatus. FIG. 6 is a time chart relating to fluids supplied to a substrate during the substrate processing. FIG. 7A is a schematic diagram for explaining the state of the substrate during the substrate processing. FIG. 7B is a schematic diagram for explaining the state of the substrate during the substrate processing. FIG. 7C is a schematic diagram for explaining the state of the substrate during the substrate processing. FIG. 7D is a schematic diagram for explaining the state of the substrate during the substrate processing. FIG. 7E is a schematic diagram for explaining the state of the substrate during the substrate processing. FIG. 8 is a schematic diagram for explaining the state near the upper surface of the substrate during the substrate processing. FIG. 9A is a schematic diagram for explaining a first example of a method for supplying an etching treatment liquid to a substrate. FIG. 9B is a schematic diagram for explaining a second example of the method for supplying the etching liquid to the substrate. FIG. 9C is a schematic diagram for explaining a third example of the method for supplying the etching liquid to the substrate. FIG. 10 is a time chart for explaining the first modified example of the substrate processing. FIG. 11 is a time chart for explaining the second modified example of the substrate processing. FIG. 12 is a plan view for illustrating the configuration of a substrate processing apparatus according to a second embodiment of the present invention. FIG. 13 is a flow chart for explaining an example of a substrate processing performed by the substrate processing apparatus. FIG. 14A is a schematic cross-sectional view for explaining a state near the upper surface of a substrate before a dry etching process is performed in substrate processing according to the second embodiment. FIG. 14B is a schematic cross-sectional view for explaining the state of the vicinity of the upper surface of the substrate after the dry etching process. FIG. 15A is a schematic diagram for explaining a modified example of the cooling member. FIG. 15B is a schematic diagram for explaining a modified example of the heating member.

Hereinafter, an embodiment of the present invention will be described with reference to the accompanying drawings.
<Structure of the surface layer of the substrate to be processed>
FIG. 1 is a schematic cross-sectional view for explaining the structure of a substrate W to be processed.
The substrate W has a pair of main surfaces. The substrate W includes a semiconductor layer 100 having the pair of main surfaces, an insulating layer 101 formed on at least one of the main surfaces of the semiconductor layer 100, a stack 102 formed on the insulating layer 101, and a mask layer 103 formed on the stack 102. The stack 102 includes a plurality of insulating layers 104 and a plurality of sacrificial layers 105. In the stack 102, the insulating layers 104 and the sacrificial layers 105 are alternately arranged.

The semiconductor layer 100 is made of, for example, single crystal Si. The insulating layer 101 is, for example, a silicon oxide film ( _SiO2 film). The insulating layer 104 and the sacrificial layer 105 constituting the laminate 102 are made of different materials, for example, the insulating layer 104 is a silicon oxide film and the sacrificial layer 105 is a silicon nitride film (SiN). The sacrificial layer 105 is replaced with an electrode layer (not shown) such as a silicon layer in a process subsequent to the substrate processing (see FIG. 5) described later. The mask layer 103 is made of, for example, amorphous carbon.

A recess 110 is formed in the area on the surface of the laminate 102 where the mask layer 103 is not formed. The recess 110 is formed in at least one of the pair of main surfaces of the substrate W. The main surface on which the recess 110 is formed is called the first main surface, and the main surface opposite the first main surface is called the second main surface. When the recess 110 is formed in both of the pair of main surfaces of the substrate W, one of the main surfaces is the first main surface, and the main surface opposite the first main surface is the second main surface. The recess 110 has an opening 111 and a bottom 112, and the depth direction DD of the recess 110 coincides with the stacking direction of the laminate 102.

The depth D of the recess 110 is, for example, 0.5 μm or more and 1.5 μm or less. The aspect ratio of the recess 110 is, for example, 20 or more and 100 or less. The recess 110 has a tapered shape that tapers from the opening 111 toward the bottom 112. The width L of the recess 110 decreases from the opening 111 toward the bottom 112. Note that the recess 110 may have a tapered shape that tapers from the opening 111 toward the bottom 112 even if this dimensional relationship is not met.

The laminate 102 has a pair of side walls 106 that are inclined in the depth direction DD so as to approach each other from the opening 111 toward the bottom 112, and a bottom wall 107 that connects the pair of side walls 106. Each side wall 106 includes an opening side wall portion 108 that defines the opening 111 of the recess 110, and a bottom side wall portion 109 that defines the bottom 112 side of the opening 111 of the recess 110.

<Configuration of the Substrate Processing Apparatus According to the First Embodiment>
Fig. 2A is a plan view for explaining the configuration of the substrate processing apparatus 1 according to the first embodiment of the present invention, and Fig. 2B is an elevational view for explaining the configuration of the substrate processing apparatus 1.
The substrate processing apparatus 1 is a single-wafer processing apparatus that processes a single substrate W. In this embodiment, the substrate W has a disk shape. In this embodiment, the substrate W is processed in an orientation in which a first main surface on which a recess 110 (see FIG. 1 ) is formed faces upward.

The substrate processing apparatus 1 includes a plurality of processing units 2 for processing substrates W, a load port LP on which a carrier C is placed which contains a plurality of substrates W to be processed in the processing units 2, transport robots IR and CR which transport the substrates W between the load port LP and the processing units 2, and a controller 3 which controls the substrate processing apparatus 1.
The transport robot IR transports the substrate W between the carrier C and the transport robot CR. The transport robot CR transports the substrate W between the transport robot IR and the processing unit 2.

Each of the transport robots IR, CR is, for example, a multi-joint arm robot including a pair of multi-joint arms AR and a pair of hands H (see Figure 2B) respectively provided at the tips of the pair of multi-joint arms AR so as to be spaced apart from each other above and below.
The processing units 2 form four processing towers TW arranged at four horizontally spaced positions. Each processing tower TW includes multiple (e.g., three) processing units 2 stacked vertically. The four processing towers TW are arranged two on each side of a transport path TR extending from a load port LP toward the transport robots IR and CR.

In the first embodiment, the processing units 2 are wet processing units 2W that process the substrate W with a liquid. Each wet processing unit 2W includes a chamber 4 and a processing cup 7 arranged in the chamber 4, and performs processing on the substrate W in the processing cup 7.
The chamber 4 is formed with an entrance (not shown) through which the transport robot CR loads and unloads the substrate W. The chamber 4 is provided with a shutter unit (not shown) that opens and closes the entrance.

FIG. 3 is a schematic cross-sectional view for explaining an example of the configuration of the wet processing unit 2W.
The wet processing unit 2W further includes a spin chuck 5 that rotates the substrate W about a rotation axis A1 (vertical axis) while holding the substrate W at a predetermined holding position. The rotation axis A1 passes through the center of the substrate W and is perpendicular to each main surface of the substrate W. That is, the rotation axis A1 extends vertically. The holding position is the position of the substrate W shown in FIG. 3, where the substrate W is held in a horizontal position.

The spin chuck 5 includes a spin base 21 having a horizontally extending disk shape, a plurality of chuck pins 20 that grip the substrate W above the spin base 21 and hold the substrate W in a holding position, a rotation shaft 22 that extends vertically and has its upper end connected to the spin base 21, and a rotation drive mechanism 23 that rotates the rotation shaft 22 around its central axis (rotation axis A1). The spin chuck 5 is an example of a substrate holding member that rotates the substrate W around the rotation axis A1 while holding the substrate W in a holding position.

The multiple chuck pins 20 are arranged on the upper surface of the spin base 21 at intervals in the circumferential direction of the spin base 21. The rotation drive mechanism 23 is, for example, an actuator such as an electric motor. The rotation drive mechanism 23 rotates the rotation shaft 22, thereby rotating the spin base 21 and the multiple chuck pins 20 around the rotation axis A1. As a result, the substrate W is rotated around the rotation axis A1 together with the spin base 21 and the multiple chuck pins 20.

The multiple chuck pins 20 are movable between a closed position in which they contact the peripheral edge of the substrate W to grip the substrate W, and an open position in which they are retracted from the peripheral edge of the substrate W. The multiple chuck pins 20 are moved by an opening/closing mechanism (not shown). When positioned in the closed position, the multiple chuck pins 20 grip the peripheral edge of the substrate W to hold the substrate W horizontally. The opening/closing mechanism includes, for example, a link mechanism and an actuator that applies a driving force to the link mechanism.

The processing cup 7 receives liquid splashed from the substrate W held on the spin chuck 5. The processing cup 7 includes a plurality of guards 30 (two in the example of FIG. 3) that receive liquid splashed outward from the substrate W held on the spin chuck 5, a plurality of cups 31 (two in the example of FIG. 3) that receive liquid guided downward by the guards 30, and a cylindrical outer wall member 32 that surrounds the guards 30 and cups 31. The guards 30 are individually raised and lowered by a guard lifting drive mechanism (not shown). The guard lifting drive mechanism includes, for example, an actuator such as an electric motor or an air cylinder that drives each guard 30 to raise and lower.

The wet processing unit 2W further includes an etching processing liquid nozzle 10 that supplies an etching processing liquid to the upper surface (upper main surface) of the substrate W held on the spin chuck 5, and a rinsing liquid nozzle 11 that supplies a rinsing liquid to the upper surface of the substrate W held on the spin chuck 5.
The etching solution contains an etching component and a gelling agent as solutes, and a solvent for dissolving the solutes. The solvent contained in the etching solution is, for example, water such as deionized water (DIW). However, the solvent is not limited to DIW.

The etching component has a property of etching the stack 102 (see FIG. 1) of the substrate W. More specifically, the etching component etches a portion (a pair of side walls 106) that defines the recess 110 in the stack 102. The etching component is, for example, hydrofluoric acid or APM (ammonia-hydrogen peroxide mixture). Strictly speaking, the etching component is an etching ion, and is HF ₂ ⁻ or NH ₄ ⁺ .

The gelling agent is, for example, gelatin, agar, or a mixture thereof. The melting point and freezing point of the gelling agent are usually different from each other, and the melting point of the gelling agent is higher than the freezing point of the gelling agent. The melting point of the gelling agent is, for example, 20°C or higher and 30°C or lower, and the freezing point of the gelling agent is, for example, 15°C or higher and 25°C or lower. The melting point and freezing point of the gelling agent vary depending on the blending ratio (concentration) of the gelling agent in the etching processing liquid, the type of gelling agent, etc. It is preferable that the freezing point of the gelling agent is lower than the room temperature (for example, 25°C) in the clean room in which the substrate processing apparatus 1 is placed.

The melting point and freezing point of the gelling agent are not limited to the above ranges. For example, when the gelling agent is agar, the melting point of the gelling agent is 85° C. or more and 93° C. or less, and the freezing point of the gelling agent is 33° C. or more and 45° C. or less.
The etching liquid is changed into an etching gel by being cooled below the freezing point of the gelling agent. The change of the etching liquid into an etching gel is called gelation. The etching gel is changed into an etching liquid by being heated above the melting point of the gelling agent. The change of the etching gel into an etching liquid is called solization. Therefore, the etching liquid is also called an etching sol.

Compared to the etching treatment liquid, the etching gel has a lower etching performance for etching the substrate W. Therefore, etching of the substrate W can be stopped by changing the etching treatment liquid adhering to the upper surface of the substrate W into the etching gel, and etching of the substrate W can be started by changing the etching gel into the etching treatment liquid.
The rinse liquid is, for example, water such as DIW. The rinse liquid is not limited to DIW, but is a component containing at least one of DIW, carbonated water, electrolytic ion water, diluted hydrochloric acid water (for example, 1 ppm or more and 100 ppm or less), diluted ammonia water (for example, 1 ppm or more and 100 ppm or less), and reduced water (hydrogen water).

The etching liquid nozzle 10 and the rinsing liquid nozzle 11 are both movable nozzles that can move at least in the horizontal direction. The etching liquid nozzle 10 and the rinsing liquid nozzle 11 are each moved in the horizontal direction by a plurality of nozzle movement mechanisms (a first nozzle movement mechanism 35 and a second nozzle movement mechanism 36). Each nozzle movement mechanism includes an arm (not shown) that supports the corresponding nozzle, and an arm movement mechanism (not shown) that moves the corresponding arm in the horizontal direction. Each arm movement mechanism includes an actuator such as an electric motor or an air cylinder. Unlike this embodiment, the etching liquid nozzle 10 and the rinsing liquid nozzle 11 may be configured to move together by a common nozzle movement mechanism.

The etching processing liquid nozzle 10 and the rinsing liquid nozzle 11 may be configured so as to be movable also in the vertical direction.
The etching treatment liquid nozzle 10 is connected to an etching treatment liquid pipe 40 that guides the etching treatment liquid to the etching treatment liquid nozzle 10. An etching treatment liquid valve 50A that opens and closes a flow path in the etching treatment liquid pipe 40, and an etching treatment liquid flow rate adjustment valve 50B that adjusts the flow rate of the etching treatment liquid in the flow path are interposed in the etching treatment liquid pipe 40.

When the etching liquid valve 50A is opened, the etching liquid is discharged downward in a continuous flow from the discharge port of the etching liquid nozzle 10 at a flow rate according to the opening of the etching liquid flow rate adjustment valve 50B. The etching liquid nozzle 10 is an example of an etching liquid supply member. The temperature of the etching liquid discharged from the etching liquid nozzle 10 is higher than the freezing point of the gelling agent.

The rinsing liquid nozzle 11 is connected to a rinsing liquid pipe 41 that guides the rinsing liquid to the rinsing liquid nozzle 11. A rinsing liquid valve 51A that opens and closes a flow path in the rinsing liquid pipe 41, and a rinsing liquid flow rate adjustment valve 51B that adjusts the flow rate of the rinsing liquid in the flow path are provided in the rinsing liquid pipe 41.
When the rinsing liquid valve 51A is opened, the rinsing liquid is discharged downward in a continuous flow from the discharge port of the rinsing liquid nozzle 11 at a flow rate that corresponds to the opening degree of the rinsing liquid flow rate adjustment valve 51B. The rinsing liquid nozzle 11 is an example of a rinsing liquid supplying member.

The wet processing unit 2W further includes a lower fluid nozzle 12 which supplies a fluid to the lower surface (lower main surface) of the substrate W held on the spin chuck 5.
The lower fluid nozzle 12 is inserted into the internal space of the rotation shaft 22 and into a through-hole 21a that opens in the center of the upper surface of the spin base 21. The outlet 12a of the lower fluid nozzle 12 is exposed from the upper surface of the spin base 21. The outlet 12a of the lower fluid nozzle 12 faces a central region of the lower surface of the substrate W from below. The central region of the lower surface of the substrate W refers to a region on the lower surface of the substrate W that includes the center of rotation of the substrate W.

The lower fluid nozzle 12 selectively supplies, to the underside of the substrate W, fluids such as a cooling fluid having a temperature below the freezing point of the gelling agent and a heating fluid having a temperature above the melting point of the gelling agent.
The cooling fluid is, for example, water at 5° C. or more and 15° C. or less, i.e., cold water. The heating fluid is, for example, water at 40° C. or more and 50° C. or less, i.e., hot water. The cooling fluid and the heating fluid may be liquids other than water. The cold water and the hot water are preferably DIW.

By cooling the underside of the substrate W with a cooling fluid, the underside of the substrate W can be cooled to a temperature below the freezing point of the gelling agent. By heating the underside of the substrate W with a heating fluid, the underside of the substrate W can be heated to a temperature above the melting point of the gelling agent. The lower fluid nozzle 12 is an example of a cooling member that cools the underside (second main surface) of the substrate W to a temperature below the freezing point of the gelling agent, and is an example of a heating member that heats the underside (second main surface) of the substrate W to a temperature above the melting point of the gelling agent.

The cooling fluid and the heating fluid do not have to be liquids, and may be inert gases such as nitrogen gas, rare gases, etc. The inert gas is a gas whose reactivity with the main surface of the substrate W is negligibly low.
In the substrate processing described below (see FIG. 5), an example will be described in which the heating fluid is hot water and the cooling fluid is cold water.

The lower fluid nozzle 12 is connected to one end of a fluid pipe 42 that guides a fluid to the lower fluid nozzle 12. The other end of the fluid pipe 42 is connected to a cooling fluid pipe 43 that supplies a cooling fluid to the fluid pipe 42, and a heating fluid pipe 44 that supplies a heating fluid to the fluid pipe 42.
Fluid may be supplied from separate fluid tanks (not shown) to the cooling fluid pipe 43 and the heating fluid pipe 44. Specifically, the cooling fluid may be supplied to the cooling fluid pipe 43 from a cooling fluid tank that stores the cooling fluid, and the heating fluid may be supplied to the heating fluid pipe 44 from a heating fluid tank that stores the heating fluid.

A common fluid tank (not shown) is connected to the cooling fluid pipes 43 and the heating fluid pipes 44, and the temperature of the fluid may be adjusted as the fluid is sent from the fluid tank to each pipe (the cooling fluid pipes 43 and the heating fluid pipes 44).
A fluid valve 52A that opens and closes the flow path in the fluid pipe 42 and a fluid flow rate adjustment valve 52B that adjusts the flow rate of the fluid in the flow path are provided in the fluid pipe 42. A cooling fluid valve 53 that opens and closes the flow path in the cooling fluid pipe 43 is provided in the cooling fluid pipe 43, and a cooling fluid valve 53 that opens and closes the flow path in the heating fluid pipe 44 is provided in the heating fluid pipe 44.

FIG. 4 is a block diagram for explaining a configuration example regarding control of the substrate processing apparatus 1. As shown in FIG.
The controller 3 includes a microcomputer and controls the controlled objects included in the substrate processing apparatus 1 in accordance with a predetermined program. More specifically, the controller 3 includes a processor (CPU) 3A and a memory 3B in which a program is stored, and is configured to execute various control processes for substrate processing by the processor 3A executing the program.

In particular, the controller 3 is programmed to control the components (valves, motors, etc.) constituting the wet processing unit 2W, the transport robots IR, CR, etc. The controller 3 also controls the components (valves, motors, power supplies, etc.) constituting a dry processing unit 2D (see FIG. 12) described later in the same manner.
The controller 3 controls the valves to control whether or not the fluid is discharged from the corresponding nozzle and the flow rate of the fluid discharged from the corresponding nozzle. Each of the following steps is executed by the controller 3 controlling each member provided in the substrate processing apparatus 1. In other words, the controller 3 is programmed to execute each of the following steps.

<Example of substrate processing>
Fig. 5 is a flow chart for explaining an example of substrate processing executed by the substrate processing apparatus 1. Fig. 5 mainly shows processing that is realized by the controller 3 executing a program.
Fig. 6 is a time chart relating to fluids supplied to a substrate W during substrate processing. "Discharge" in Fig. 6 indicates that fluid is being discharged from the corresponding nozzle, and "Stop" indicates that discharge of fluid from the corresponding nozzle is stopped. Also, "cold water" in Fig. 6 means that cold water is being discharged from the lower fluid nozzle 12, and "hot water" in Fig. 6 indicates that hot water is being discharged from the lower fluid nozzle 12. The same applies to Figs. 10 and 11 described below.

7A to 7E are schematic views for explaining the state of each process of the substrate processing performed by the substrate processing apparatus 1. FIG.
In the substrate processing by the substrate processing apparatus 1, for example, as shown in FIG. 5, a substrate loading step (step S1), an etching treatment liquid supply step (step S2), a cooling step (step S3), a rinsing liquid supply step (step S4), a heating step (step S5), a supply resumption step (step S6), spin drying (step S7), and a substrate unloading step (step S8) are performed in this order.

The substrate processing performed by the substrate processing apparatus 1 will be described below mainly with reference to Figures 3, 5 and 6. Figures 7A to 7E will also be referenced as appropriate.
First, an unprocessed substrate W is carried from the carrier C into the wet processing unit 2W by the transport robots IR, CR (see FIG. 2A) and handed over to the spin chuck 5 (substrate carrying-in process: step S1). As a result, the substrate W is held horizontally by the spin chuck 5 (substrate holding process). The spin chuck 5 continues to hold the substrate W until the spin dry process (step S7) is completed. With the substrate W held by the spin chuck 5, the rotary drive mechanism 23 starts rotating the substrate W (substrate rotation process).

Next, after the transport robot CR retreats to the outside of the processing unit 2, an etching liquid supplying step (step S2) of supplying an etching liquid to the upper surface of the substrate W is performed.
Specifically, the first nozzle moving mechanism 35 moves the etching processing liquid nozzle 10 to the processing position, and the etching processing liquid valve 50A is opened while the etching processing liquid nozzle 10 is located at the processing position. As a result, as shown in Fig. 7A, the etching processing liquid is discharged from the etching processing liquid nozzle 10 toward the upper surface of the substrate W (etching processing liquid discharge step). The etching processing liquid discharged from the etching processing liquid nozzle 10 lands on the upper surface of the substrate W. The etching processing liquid is spread over the entire upper surface of the substrate W by the action of centrifugal force, and is supplied to the entire upper surface of the substrate W (etching processing liquid supply step).

In this substrate processing, the processing position of the etching processing liquid nozzle 10 is a central position where the discharge port of the etching processing liquid nozzle 10 faces the central region of the upper surface of the substrate W. The central region of the upper surface of the substrate W is a region on the upper surface of the substrate W that includes the center of rotation of the substrate W. Therefore, the etching processing liquid lands in the central region of the upper surface of the substrate W. Unlike this substrate processing, the etching processing liquid nozzle 10 may discharge the etching processing liquid while moving horizontally along the upper surface of the substrate W.

After the etching liquid supplying step (step S2), a cooling step (step S3) is performed to cool the lower surface of the substrate W with cold water.
Specifically, the etching liquid valve 50A is closed to stop the discharge of the etching liquid, and instead, the fluid valve 52A and the cooling fluid valve 53 are opened. As a result, cold water is discharged from the lower fluid nozzle 12 toward the lower surface of the substrate W (cold water discharge step, cooling fluid discharge step). The cold water discharged from the lower fluid nozzle 12 lands (collides) on the central region of the lower surface of the substrate W. The cold water spreads over the entire lower surface of the substrate W by the action of centrifugal force, and is supplied to the entire lower surface of the substrate W (cold water supply step, cooling fluid supply step). As a result, the substrate W is cooled from below (the second main surface side). Since the substrate W is cooled by the cold water, the etching liquid attached to the upper surface of the substrate W gels, and an etching gel 120 is formed on the upper surface (gelling step).

After the discharge of the etching processing liquid is stopped, the etching processing liquid nozzle 10 is moved to the retracted position by the first nozzle moving mechanism 35. The retracted position of the etching processing liquid nozzle 10 is a position that does not face the upper surface of the substrate W and is located outside the processing cup 7 in a plan view.
After the cooling step (step S3), a rinsing liquid supplying step (step S4) is performed in which a rinsing liquid is supplied to the upper surface of the substrate W while continuing to cool the lower surface of the substrate W. Continuing to cool the lower surface of the substrate W does not mean to further reduce the temperature of the substrate W, but means to continue to supply cold water to the lower surface of the substrate W regardless of changes in the temperature of the substrate W.

In the rinsing liquid supply process (step S4), specifically, the second nozzle movement mechanism 36 moves the rinsing liquid nozzle 11 to the processing position, and with the rinsing liquid nozzle 11 positioned at the processing position, the rinsing liquid valve 51A is opened. As a result, as shown in FIG. 7C, rinsing liquid is discharged from the rinsing liquid nozzle 11 toward the upper surface of the substrate W (rinsing liquid discharge process). The rinsing liquid discharged from the rinsing liquid nozzle 11 lands on the upper surface of the substrate W. The rinsing liquid spreads over the entire upper surface of the substrate W due to the action of centrifugal force, and is supplied to the entire upper surface of the substrate W (rinsing liquid supply process, first rinsing liquid supply process).

In this substrate processing, the processing position of the rinsing liquid nozzle 11 is a central position where the discharge port of the rinsing liquid nozzle 11 faces a central region of the upper surface of the substrate W. Therefore, the rinsing liquid lands in the central region of the upper surface of the substrate W. Unlike this substrate processing, the rinsing liquid nozzle 11 may discharge the rinsing liquid while moving horizontally along the upper surface of the substrate W.
In the rinse liquid supply step, the fluid valve 52A and the cooling fluid valve 53 are maintained in an open state. As a result, as shown in Fig. 7C, the rinse liquid is supplied to the upper surface of the substrate W while cold water is supplied to the lower surface of the substrate W. Since the temperature of the rinse liquid discharged from the rinse liquid nozzle 11 is equal to or higher than the melting point of the gelling agent, the etching gel 120 (see Fig. 7B) on the upper surface of the substrate W is heated by the rinse liquid and changes into an etching treatment liquid, which is discharged outside the substrate W together with the rinse liquid. However, as will be described in detail later, since the substrate W is cooled from below, the etching gel 120 remains in the recess 110 (see Fig. 1) formed on the upper surface of the substrate W.

After the rinsing liquid supplying step (step S3), a heating step (step S4) is carried out in which the lower surface of the substrate W is heated with hot water.
Specifically, the rinsing liquid valve 51A and the cooling fluid valve 53 are closed, and instead, the heating fluid valve 54 is opened. As a result, as shown in Fig. 7D, the supply of the rinsing liquid from the rinsing liquid nozzle 11 to the upper surface of the substrate W is stopped (rinsing liquid supply stopping step), and the supply of cold water from the lower fluid nozzle 12 to the lower surface of the substrate W is stopped (cooling fluid supply stopping step, cold water supply stopping step).

When the heating fluid valve 54 is opened, hot water is discharged from the lower fluid nozzle 12 toward the underside of the substrate W (heating fluid discharge process, hot water discharge process). The hot water discharged from the lower fluid nozzle 12 collides with the underside of the substrate W. The hot water spreads over the entire underside of the substrate W due to the action of centrifugal force, and is supplied to the entire underside of the substrate W (heating fluid supply process, hot water supply process). This causes the substrate W to be heated from below (the second main surface side). In other words, cooling of the substrate W is stopped (cooling stop process).

As described in detail below, the substrate W is heated by the hot water, so that the etching gel 120 remaining on the upper surface of the substrate W changes into an etching treatment liquid (solation process). The substrate W is etched by the etching treatment liquid formed by the solation of the etching gel 120 (etching process).
After the discharge of the rinsing liquid from the rinsing liquid nozzle 11 is stopped, the rinsing liquid nozzle 11 is maintained at the processing position, which can eliminate the need to move the rinsing liquid nozzle 11 again in a supply restart step described later.

After the discharge of the rinsing liquid is stopped, the rinsing liquid nozzle 11 may be moved to a retracted position by the second nozzle moving mechanism 36. The retracted position of the rinsing liquid nozzle 11 is a position that does not face the upper surface of the substrate W and is located outside the processing cup 7 in a plan view.
After the heating step (step S5), a supply resumption step (step S6) is performed in which the rinsing liquid is again supplied to the upper surface of the substrate W while continuing to heat the substrate W. Continuing to heat the substrate W does not mean to further increase the temperature of the substrate W, but means to continue to supply hot water to the substrate W regardless of a change in the temperature of the substrate W.

In the supply restart process (step S6), specifically, the rinse liquid valve 51A is opened. As a result, as shown in FIG. 7E, rinse liquid is discharged from the rinse liquid nozzle 11 toward the upper surface of the substrate W (rinse liquid discharge process). The rinse liquid discharged from the rinse liquid nozzle 11 lands on the upper surface of the substrate W. The rinse liquid spreads over the entire upper surface of the substrate W by the action of centrifugal force and is supplied to the entire upper surface of the substrate W (rinse liquid supply restart process, second rinse liquid supply process). Since the temperature of the rinse liquid discharged from the rinse liquid nozzle 11 is equal to or higher than the melting point of the gelling agent, the etching treatment liquid remaining on the upper surface of the substrate W can be discharged together with the rinse liquid to the outside of the substrate W without changing it into an etching gel.

In the supply resumption step (step S6), the fluid valve 52A and the heating fluid valve 54 are maintained in an open state. As a result, while the rinsing liquid is being supplied to the upper surface of the substrate W, hot water is supplied to the lower surface of the substrate W, and the heating of the substrate W is assisted by the hot water (auxiliary heating step), as shown in FIG.
Next, a spin dry process (step S7) is performed in which the substrate W is rotated at high speed to dry the upper surface of the substrate W. Specifically, the rinsing liquid valve 51A, the fluid valve 52A, and the heating fluid valve 54 are closed. This stops the supply of the rinsing liquid to the upper surface of the substrate W and the supply of the heating fluid to the lower surface of the substrate W.

Then, the rotation drive mechanism 23 accelerates the rotation of the substrate W, rotating it at high speed. The substrate W is rotated at a drying speed, for example, 1500 rpm. As a result, a large centrifugal force acts on the rinsing liquid adhering to the upper surface of the substrate W and the warm water adhering to the lower surface of the substrate W, causing these liquids to be thrown off around the substrate W. After that, the rotation drive mechanism 23 stops the rotation of the substrate W.

After the spin dry process (step S7), the rotation drive mechanism 23 stops the rotation of the substrate W. Then, the transport robot CR enters the wet processing unit 2W, receives the processed substrate W from the spin chuck 5, and transports it out of the wet processing unit 2W (substrate unloading process: step S8). The substrate W is passed from the transport robot CR to the transport robot IR, which stores it in the carrier C.

8 is a schematic diagram for explaining the state near the upper surface of the substrate W during substrate processing. In order to simplify the illustration, the entire stack 102 is illustrated as a cross section of one layer in Fig. 8, but in reality, the stack 102 includes a plurality of insulating layers 104 and a plurality of sacrificial layers 105.
In the etching liquid supplying step (step S2), the etching liquid is supplied to the upper surface of the substrate W, so that the etching liquid 90 is filled into the recess 110 as shown in FIG. 8A (etching liquid filling step).

After that, in the cooling process (step S3), the substrate W is cooled from the lower surface side of the substrate W by cold water. As a result, the etching treatment liquid 90 is cooled through the substrate W, and the temperature of the etching treatment liquid 90 on the upper surface of the substrate W reaches a temperature below the freezing point of the gelling agent. As a result, as shown in FIG. 8(b), the etching treatment liquid 90 changes into an etching gel 120 (gelling process). The etching gel 120 is also formed in the recess 110. In other words, the etching gel 120 includes an inner gel 121 located in the recess 110 and an outer gel 122 located outside the recess 110.

After that, in the rinse liquid supply process (step S4), the temperature of the rinse liquid discharged from the rinse liquid nozzle 11 is equal to or higher than the melting point of the gelling agent. Therefore, when the rinse liquid 91 is supplied to the upper surface of the substrate W, the outer gel 122 changes into an etching treatment liquid. The etching treatment liquid formed by the solation of the outer gel 122 is discharged outside the substrate W together with the rinse liquid. By continuing to supply the rinse liquid even after the outer gel 122 is solated, the portion of the inner gel 121 located at the opening 111 of the recess 110 (opening side portion 123) changes into an etching treatment liquid.

The etching liquid formed by the solation of the opening side portion 123 is replaced by the rinsing liquid and removed from within the recess 110. Thereafter, the etching liquid formed by the solation of the opening side portion 123 is discharged outside the substrate W together with the rinsing liquid. In this way, the opening side portion 123 is transformed into the etching liquid and removed from the recess 110 (opening side portion removal process).

On the other hand, the bottom side portion 124 of the inner gel 121, which is closer to the bottom 112 than the opening side portion 123, is closer to the underside than the opening side portion 123 and is therefore more susceptible to cooling by cold water. Therefore, as shown in FIG. 8(c), even though a rinsing liquid having a temperature equal to or higher than the melting point of the gelling agent is supplied to the upper surface of the substrate W, the bottom side portion 124 can be maintained in a gel state.

The amount of the inner gel 121 removed by the rinse liquid 91 can be adjusted by adjusting the supply flow rate of the cold water, the supply flow rate of the rinse liquid 91, etc. It is preferable that the inner gel 121 on the opening 111 side rather than the center of the recess 110 in the depth direction DD is removed by the rinse liquid 91.
After the rinsing liquid supplying step (step S4), in the heating step (step S5), the substrate W is heated from the lower surface side of the substrate W by hot water. As a result, the inner gel 121 is heated through the substrate W, and the temperature of the inner gel 121 reaches a temperature equal to or higher than the melting point of the gelling agent. As a result, as shown in FIG. 8D, the bottom portion 124 remaining in the recess 110 is transformed into the etching treatment liquid 90 (solization step).

In this way, in the heating step, after the supply of the rinsing liquid to the first main surface is stopped, the temperature of the etching gel 120 remaining in the recess 110 can be quickly increased to change the etching gel 120 remaining in the recess 110 into the etching treatment liquid 90. Therefore, etching of the substrate W can be started quickly.
During the heating step (step S5), while hot water is being supplied to the lower surface of the substrate W, the supply of the rinsing liquid 91 to the upper surface of the substrate W is stopped. Therefore, the etching treatment liquid 90 formed by the solation of the bottom portion 124 is not immediately replaced by the rinsing liquid 91, and the etching components 92 diffuse into the rinsing liquid 91 that comes into contact with the etching treatment liquid 90 (etching component diffusion step).

As a result, the portion defining the recess 110 is etched on the upper surface of the substrate W (etching step). Details of the etching are as follows.
As shown in FIG. 8E, a concentration gradient of the etching component 92 is generated in the recess 110 such that the concentration of the etching component 92 decreases from the bottom 112 of the recess 110 toward the opening 111. Therefore, an etching rate gradient is generated from the opening 111 of the recess 110 toward the bottom 112. In detail, the etching rate is higher on the bottom 112 side than on the opening 111 side. Therefore, the etching amount of the pair of side walls 106 of the stack 102 is larger closer to the bottom 112 in the depth direction DD of the recess 110. As a result, the width L of the recess 110 on the bottom 112 side is expanded so that the recess 110 approaches a straight shape. As a result, the uniformity of the width L of the recess 110 in the depth direction DD of the recess 110 provided on the upper surface of the substrate W can be improved.

In the supply resumption step (step S6), the supply of the rinsing liquid 91 to the upper surface of the substrate W is resumed. Since the temperature of the rinsing liquid 91 is higher than the melting point of the gelling agent, the etching treatment liquid 90 in the recess 110 can be prevented from changing back into an etching gel. By resupplying the rinsing liquid, the etching treatment liquid in the recess 110 can be removed from the recess 110 by the rinsing liquid 91, as shown in FIG. 8(f) (etching treatment liquid removal step).

In the supply resumption process (step S6), the rinsing liquid replaces the etching liquid 90 in the recess 110 after the etching components in the etching liquid 90 have diffused within the recess 110 and the width L of the recess 110 on the bottom 112 side has been appropriately widened. As a result, the uniformity of the width L of the recess 110 in the depth direction DD of the recess 110 provided on the upper surface of the substrate W can be improved.

In addition, in the supply resumption process (step S6), heating of the substrate W is started, the temperature of the etching gel 120 remaining in the recess 110 increases, and the etching gel 120 remaining in the recess 110 changes into the etching treatment liquid 90. After the etching gel 120 remaining in the recess 110 changes into the etching treatment liquid 90, the supply of the rinsing liquid 91 to the upper surface of the substrate W is resumed.

In addition, while the rinsing liquid 91 is being supplied to the substrate W in the supply resumption step (step S6), the substrate W is heated from below by the warm water. That is, when the rinsing liquid is supplied to the upper surface (first main surface) to remove the etching treatment liquid 90 in the recess 110, the substrate W is heated from the lower surface side (second main surface side) (auxiliary heating step). This makes it possible to prevent the temperature of the etching treatment liquid 90 in the recess 110 from decreasing while the rinsing liquid 91 is being supplied. This makes it possible to prevent the etching treatment liquid 90 in the recess 110 from changing into an etching gel 120 and causing etching components to remain in the recess 110.

Thereafter, in a spin dry process (step S7), the rinsing liquid is removed from the recess 110, thereby drying the upper surface of the substrate W.
According to the first embodiment, the substrate W on which the recesses 110 are already formed can be further etched to improve the uniformity of the widths L of the recesses 110 in the depth direction DD of the recesses 110 .

According to the first embodiment, the uniformity of the width L of the recess 110 can be improved without forming the mask layer 103 into a laminated structure, so that the formation of the mask layer 103 can be simplified.
Furthermore, according to the first embodiment, the underside of the substrate W can be heated by the simple method of supplying a heating fluid such as warm water, and the underside of the substrate W can be cooled by the simple method of supplying a cooling fluid such as cold water.

Here, when the gelling agent is agar, the melting point of the gelling agent is 85° C. or more and 93° C. or less, and the freezing point of the gelling agent is 33° C. or more and 45° C. or less. When a gelling agent having a melting point and a freezing point in such a temperature range is used, unlike the above-mentioned embodiment, the temperature of the heating fluid is, for example, 85° C. or more, and the temperature of the cooling fluid is 33° C. or less. In other words, the temperature of the cooling fluid may be higher than room temperature. Even in this case, the temperature of the etching processing liquid supplied to the upper surface of the substrate W is naturally higher than the freezing point and higher than 33° C., and is therefore cooled by the cooling fluid.
When the solidification point of the gelling agent is 33° C. or higher and 45° C. or lower, it is also possible to use hot water at a temperature higher than room temperature as the cooling fluid.

<Method of Supplying Etching Solution>
9A to 9C are schematic views for explaining first to third examples of a method for supplying an etching processing liquid to a substrate W, respectively.
9A , an etching treatment liquid piping 40 is connected to an etching treatment liquid tank 140 that stores the etching treatment liquid, and the etching treatment liquid in the etching treatment liquid tank 140 is supplied to the etching treatment liquid nozzle 10 via the etching treatment liquid piping 40. An etching treatment liquid refill pipe 133 that refills the etching treatment liquid tank 140 with the etching treatment liquid is connected to the etching treatment liquid tank 140.

The temperature of the etching treatment liquid supplied to the etching treatment liquid nozzle 10 may be adjusted by a temperature adjustment member 134 that adjusts the temperature of the etching treatment liquid in the etching treatment liquid pipe 40. The etching treatment liquid tank 140 may be configured to adjust the temperature of the etching treatment liquid.
In the second example of the supply method shown in FIG. 9B, unlike the first example, the etching liquid and the gelling agent liquid are mixed in the etching liquid tank 140 to form the etching liquid.

The etching solution is a liquid containing an etching component and a solvent, for example, DHF (dilute hydrofluoric acid) or APM (ammonia hydrogen peroxide mixture). The gelling agent liquid is a liquid containing a gelling agent and a solvent. It is preferable that the solvent contained in the etching solution and the solvent contained in the gelling agent liquid are the same type of liquid, for example, DIW.

An etching liquid piping 40 is connected to the etching liquid tank 140, and the etching liquid in the etching liquid tank 140 is supplied to the etching liquid nozzle 10 via the etching liquid piping 40. An etching liquid refill pipe 138 that refills the etching liquid tank 140 with etching liquid, and a gelling agent liquid refill pipe 139 that refills the etching liquid tank 140 with gelling agent liquid are connected to the etching liquid tank 140.

In a third example of the supply method shown in FIG. 9C, the etching liquid and the gelling agent liquid are mixed in the mixing pipe 130 to form an etching treatment liquid, and the etching treatment liquid formed in the mixing pipe 130 is discharged from the etching treatment liquid nozzle 10 to be supplied to the upper surface of the substrate W (etching treatment liquid supply process). The mixing pipe 130 is a pipe for mixing multiple liquids, and is, for example, a mixing valve.

The etching liquid is supplied from the etching liquid tank 141 to the mixing pipe 130 via the etching liquid pipe 131. The gelling agent liquid is supplied from the gelling agent liquid tank 142 to the mixing pipe 130 via the gelling agent liquid pipe 132. The etching treatment liquid formed in the mixing pipe 130 is supplied to the etching treatment liquid nozzle 10 via the etching treatment liquid pipe 40.

The etching liquid pipe 131 and the gelling agent liquid pipe 132 are each provided with a plurality of valves (etching liquid valve 135A and gelling agent liquid valve 136A) that open and close the flow paths in the corresponding pipes. The etching liquid pipe 131 and the gelling agent liquid pipe 132 are each provided with a plurality of flow rate adjustment valves (etching liquid flow rate adjustment valve 135B and gelling agent liquid flow rate adjustment valve 136B) that adjust the flow rate of the liquid in the corresponding pipe.

<Modification of Substrate Processing According to First Embodiment>
10 and 11 are time charts for explaining a first modified example and a second modified example of the substrate processing, respectively.
6, in the first modified substrate processing shown in Fig. 10, heating of the substrate W is not performed in the supply restart step (step S6). More specifically, the rinsing liquid valve 51A is opened, while the fluid valve 52A and the heating fluid valve 54 are closed. This stops the supply of hot water to the lower surface of the substrate W, while the rinsing liquid is supplied to the upper surface of the substrate W.

Even in the first modified example of the substrate processing, the temperature of the rinse liquid discharged from the rinse liquid nozzle 11 is equal to or higher than the melting point of the gelling agent. Therefore, the rinse liquid can suppress a decrease in temperature of the etching processing liquid in the recess 110. Therefore, the etching processing liquid remaining on the upper surface of the substrate W can be discharged outside the substrate W together with the rinse liquid without changing into an etching gel.

The second modified example of the substrate processing shown in FIG. 11 differs from the substrate processing shown in FIG. 6 in that the heating step is not performed in step S5.
Specifically, in the cooling stop step (step S5), first, the rinsing liquid valve 51A and the cooling fluid valve 53 are closed to stop the discharge of the rinsing liquid and the cold water. By stopping the discharge of the cold water, the cooling of the lower surface of the substrate W is stopped (cooling stop step).

By stopping the cooling of the lower surface of the substrate W, the temperature of the substrate W gradually rises, and the etching gel 120 remaining on the upper surface of the substrate W changes into an etching treatment liquid (solization process). In order to change the etching gel 120 into an etching treatment liquid by stopping the cooling without heating the substrate W, it is preferable that the melting point of the gelling agent is lower than room temperature. The substrate W is etched by the etching treatment liquid formed by the solation of the etching treatment liquid (etching process). In the second modified example of substrate processing, in step S5, it may take more time to solize the etching gel 120 compared to when the substrate W is heated, but it is possible to solize the etching gel 120.

Although not shown, there may be a case where the substrate W is not heated by a heating fluid such as hot water in either the cooling stop step (step S5) or the supply restart step (step S6). In this case, since there is no need to provide piping or the like for supplying a heating fluid to the lower fluid nozzle 12, the configuration of the substrate processing apparatus 1 can be simplified.
Moreover, the heating of the substrate W from below does not need to be continued throughout the entire period of the cooling stop step (step S5), nor does it need to be continued throughout the entire period of the supply restart step (step S6). That is, the heating of the substrate W may be performed during a part of the period of the cooling stop step, or during a part of the period of the supply restart step. However, the longer the heating time in the cooling stop step (step S5), the more quickly the etching gel 120 can be changed into an etching treatment liquid. Furthermore, the longer the heating time in the supply restart step (step S6), the more effectively the etching gel 120 can be suppressed from becoming a solubilized.

<Configuration of the Substrate Processing Apparatus According to the Second Embodiment>
FIG. 12 is a plan view for illustrating the configuration of a substrate processing apparatus 1P according to the second embodiment.
The substrate processing apparatus 1P according to the second embodiment differs from the substrate processing apparatus 1 according to the first embodiment (see FIG. 3) mainly in that the processing unit 2 includes a wet processing unit 2W and a dry processing unit 2D. In FIG. 12, the same reference numerals as in FIG. 1 to FIG. 11 are used for the same components as in FIG. 1 and the description thereof will be omitted. The same applies to FIG. 13 to FIG. 14B described later.

In the example shown in FIG. 12, the two processing towers TW on the transport robot IR side are composed of multiple wet processing units 2W, and the two processing towers TW on the opposite side of the transport robot IR are composed of multiple dry processing units 2D. The configuration of the wet processing unit 2W according to the second embodiment is the same as the configuration of the wet processing unit 2W according to the first embodiment (the configuration shown in FIG. 3).

The dry processing unit 2D is a unit that performs a dry etching process on the upper surface of the substrate W. The dry etching process is, for example, a dry etching process using reactive ion etching (RIE). The dry processing unit 2D has, for example, a plasma generating unit 70 arranged in the chamber 4. The plasma generating unit 70 is a unit that holds the substrate W at a predetermined position and generates plasma. By supplying an etching gas to the plasma generating unit 70, ions can be collided with the upper surface of the substrate W to etch the substrate W.

<Example of Substrate Processing According to Second Embodiment>
13 is a schematic diagram for explaining the state of the substrate W during an example of substrate processing performed by the substrate processing apparatus 1P according to the second embodiment. The substrate processing according to the second embodiment differs from the substrate processing according to the first embodiment (see FIG. 5) mainly in that a dry etching process is performed on the upper surface of the substrate W by the dry processing unit 2D.

Hereinafter, differences between the substrate processing according to the second embodiment and the substrate processing according to the first embodiment (see FIG. 5) will be described mainly with reference to FIGS.
First, an unprocessed substrate W is carried from the carrier C to the dry processing unit 2D by the transport robots IR and CR (see also FIG. 12) (first carrying-in step: step S10). The substrate W carried into the dry processing unit 2D is subjected to dry etching processing (dry etching step: step S11).

After the dry etching process (step S11), the transport robot CR enters the dry processing unit 2D, receives the substrate W from the plasma generating unit 70, and transports it out of the dry processing unit 2D (first transport process: step S12). The substrate W transported out of the dry processing unit 2D is transported by the transport robot CR into the wet processing unit 2W and handed over to the spin chuck 5 (second transport process: step S13).

In the wet processing unit 2W, the etching processing liquid supply step (step S2) to the spin dry step (step S7) are performed. After that, the transport robot CR enters the wet processing unit 2W, receives the substrate W from the spin chuck 5, and unloads the substrate W from the wet processing unit 2W (second unloading step: step S14).
The substrate W unloaded from the wet processing unit 2W is handed over from the transport robot CR to the transport robot IR, and stored in the carrier C by the transport robot IR.

As shown in FIG. 14A, before the dry etching process is performed, no recesses 110 are formed in the areas of the upper surface of the substrate W where the mask layer 103 is not formed. By performing the dry etching process using the dry processing unit 2D as shown in FIG. 14B, recesses 110 can be formed in the areas of the upper surface of the substrate W where the mask layer 103 is not formed.

<Other embodiments>
The present invention is not limited to the above-described embodiment, and can be embodied in other forms.
For example, the configuration of the substrate W to be subjected to the substrate processing according to the first embodiment is not limited to that shown in Fig. 1. Any substrate W having a main surface on which a recess is formed can be used for the substrate processing according to the first embodiment. For example, the recess 110 in Fig. 1 is formed in the stack 102, but the recess 110 does not have to be formed in the stack 102, and may be formed in a portion constituted by a single insulating layer or a single semiconductor layer. The stack 102 does not have to be provided in the substrate W to be subjected to the substrate processing according to the second embodiment.

In each of the above-described embodiments, cooling and heating of the substrate W from below is performed by fluid ejected from the lower fluid nozzle 12. However, unlike each of the above-described embodiments, for example, as shown in FIG. 15A, the substrate W may be cooled by a cooling unit 150 having a cooling plate 151 as a cooling member facing the substrate W from below, or as shown in FIG. 15B, the substrate W may be heated by a heating unit 160 having a hot plate 161 as a heating member facing the substrate W from below.

The cooling unit 150 shown in FIG. 15A includes a cooling plate 151 and an elevating shaft 152 that is connected to the lower surface of the cooling plate 151 and raises and lowers the cooling plate 151. The cooling plate 151 has a cooling surface that is circular in plan view. The cooling surface is slightly smaller than the substrate W. The cooling surface is formed, for example, by the upper surface of the cooling plate 151.

The cooling plate 151 includes, for example, a built-in cooling fluid pipe 153. The built-in cooling fluid pipe 153 is connected to a cooling fluid supply pipe 154 that supplies cooling fluid to the built-in cooling fluid pipe 153, and a cooling fluid discharge pipe 155 that discharges the cooling fluid from the built-in cooling fluid pipe 153. The cooling fluid supply pipe 154 is provided with a cooling fluid supply valve 156 that opens and closes the flow path in the cooling fluid supply pipe 154.

A lifting mechanism 157 including an actuator such as a motor is connected to the lifting shaft 152. The cooling plate 151 is raised and lowered by the lifting mechanism 157 between a contact position in contact with the lower surface of the substrate W and a spaced position spaced apart from the lower surface of the substrate W. The lifting mechanism 157 includes an actuator such as an electric motor. The cooling plate 151 has a temperature below the freezing point of the gelling agent, and can cool the lower surface of the substrate W to a temperature below the freezing point of the gelling agent.

By cooling the substrate W from below with the cooling plate 151, the lower surface of the substrate W can be cooled with high uniformity over its entire area.
15B includes a hot plate 161 and an elevation shaft 162 that is connected to the lower surface of the hot plate 161 and raises and lowers the hot plate 161. The hot plate 161 has a heating surface that is circular in plan view. The heating surface is slightly smaller than the substrate W. The heating surface is formed by, for example, the upper surface of the hot plate 161.

The hot plate 161 includes, for example, a built-in heater 163. A power supply line 164 is connected to the heater 163, and power is supplied to the heater 163 from a power supply unit 165 such as a power source via the power supply line 164.
A lifting mechanism 166 including an actuator such as a motor is connected to the lifting shaft 162. The hot plate 161 is raised and lowered by the lifting mechanism 166 between a contact position in contact with the lower surface of the substrate W and a spaced position spaced from the lower surface of the substrate W. The hot plate 161 can be raised and lowered between a contact position in contact with the lower surface of the substrate W and a spaced position spaced from the lower surface of the substrate W. The lifting mechanism 166 includes an actuator such as an electric motor. The hot plate 161 has a temperature equal to or higher than the melting point of the gelling agent, and can heat the lower surface of the substrate W to a temperature equal to or higher than the melting point of the gelling agent.

By heating the substrate W from below with the hot plate 161, the underside of the substrate W can be heated with high uniformity over its entire area. Although not shown, if the configuration allows the temperature to be switched, a single plate can function as both a cooling plate and a hot plate.
It is also possible to use a fluid to cool or heat the substrate W from below, and a plate to cool or heat the substrate W from below. Specifically, a hot plate 161 may be provided between the substrate W and the spin base 21, and a cooling fluid may be discharged from the lower fluid nozzle 12 exposed from the upper surface of the hot plate 161, as shown by the two-dot chain line in Fig. 15B. Conversely, a cooling plate 151 may be provided between the substrate W and the spin base 21, and a heating fluid may be discharged from the lower fluid nozzle 12 exposed from the upper surface of the cooling plate 151, as shown by the two-dot chain line in Fig. 15A.

In each of the above-described embodiments, substrate processing is performed with the first main surface facing upward. However, unlike the above-described embodiments, substrate processing may also be performed with the first main surface facing downward. That is, an etching processing liquid and a rinsing liquid may be supplied to the lower surface of the substrate W, and a cooling fluid and a heating fluid may be supplied to the upper surface of the substrate W. Of course, when a cooling plate is used for cooling, the upper surface of the substrate W can be cooled by placing the cooling plate opposite the upper surface of the substrate W. Similarly, when a hot plate is used for heating, the upper surface of the substrate W can be heated by placing the hot plate opposite the upper surface of the substrate W.

After the discharge of the etching liquid in the etching treatment liquid supply step (step S2) is stopped, cold water is supplied toward the lower surface of the substrate W. However, the supply of cold water may be started before the discharge of the etching liquid, or may be started during the discharge of the etching liquid.
In the first embodiment described above, the substrate processing apparatus 1 is provided with a plurality of wet processing units 2W, together with the transport robots IR, CR and the controller 3. However, the substrate processing apparatus may be configured with only a single wet processing unit 2W. In other words, the wet processing unit 2W may be an example of the substrate processing apparatus.

The dry etching process may also be performed using a dry processing device provided separately from the substrate processing apparatus 1. That is, the substrate processing apparatus 1 is provided with only a wet processing unit 2W as the processing unit 2, and the dry etching process may be performed using the dry processing device on the substrate W before the substrate processing is performed in the wet processing unit 2W.

In the above embodiment, the terms "horizontal" and "vertical" are used, but they do not necessarily have to be strictly "horizontal" and "vertical." In other words, these terms allow for deviations in manufacturing precision, installation precision, and the like.
In addition, various modifications can be made within the scope of the claims.

1: Substrate processing apparatus 1P: Substrate processing apparatus 2W: Wet processing unit (substrate processing apparatus)
2D: Dry processing unit 10: Etching processing liquid nozzle (etching processing liquid supply member)
11: Rinse liquid nozzle (rinse liquid supply member)
12: Lower fluid nozzle (cooling member, heating member)
90: Etching solution 91: Rinse solution 92: Etching component 110: Recess 111: Opening 112: Bottom 120: Etching gel 123: Opening side portion 124: Bottom side portion (gel remaining in the recess)
151: Cooling plate (cooling member)
161: Hot plate (heating member)
D: Depth W: Substrate

Claims (20)

1. A substrate processing method for processing a substrate having a first main surface and a second main surface opposite to the first main surface, comprising:
an etching treatment liquid supplying step of supplying an etching treatment liquid containing an etching component and a gelling agent to the first main surface;
a cooling step of cooling the second main surface to a temperature equal to or lower than a freezing point of the gelling agent after the etching treatment liquid supplying step;
a rinsing liquid supplying step of supplying a rinsing liquid having a temperature equal to or higher than a melting point of the gelling agent to the first main surface while continuing to cool the second main surface;
the cooling stopping step of stopping cooling of the second main surface after the rinsing liquid supplying step. The substrate processing method according to claim 1, wherein the cooling stop step includes a heating step of heating the second main surface to a temperature equal to or higher than the melting point. The substrate processing method according to claim 2, wherein the heating step includes a step of heating the substrate from the second main surface side by supplying a heating fluid having a temperature equal to or higher than the melting point to the second main surface. The substrate processing method according to claim 2 or 3, wherein the heating step includes a step of heating the substrate from the second main surface side by a hot plate facing the second main surface from below and having a temperature equal to or higher than the melting point. The substrate processing method according to any one of claims 1 to 4, wherein the cooling step includes a step of cooling the substrate from the second main surface side by supplying a cooling fluid having a temperature below the freezing point to the second main surface. The substrate processing method according to claim 5, wherein the cooling step includes a step of cooling the substrate from the second main surface side by a cooling plate facing the second main surface from below and having a temperature below the freezing point. The substrate processing method according to any one of claims 1 to 6, wherein a recess having an opening and a bottom is formed on the first main surface of the substrate. The depth of the recess is 0.5 μm or more and 1.5 μm or less,
The substrate processing method according to claim 7 , wherein the recess has an aspect ratio of 20 or more and 100 or less. the cooling step includes a gelling step of changing the etching solution in the recess into a gel;
the rinsing liquid supplying step includes an opening side portion removing step of changing an opening side portion of the gel located at the opening of the recess into the etching liquid and removing the opening side portion from the recess,
The substrate processing method according to claim 8 , wherein the cooling stopping step includes a solation step of converting the gel remaining in the recess into the etching processing liquid. The substrate processing method according to claim 9, further comprising an etching component diffusing step of diffusing the etching components in the etching processing liquid formed by the solation step into the rinsing liquid that has entered the recess in the rinsing liquid supplying step. The method further includes a supply resumption step of resuming the supply of the rinsing liquid after the cooling stopping step,
11. The substrate processing method according to claim 9, wherein the supply resumption step includes an etching processing liquid removal step of removing the etching processing liquid formed in the solation step by using the rinsing liquid. The substrate processing method according to any one of claims 1 to 8, further comprising a supply restart step of restarting the supply of the rinsing liquid after the cooling stop step. The substrate processing method according to claim 11 or 12, further comprising an auxiliary heating step of heating the substrate from the second main surface side while the rinsing liquid is being supplied to the substrate in the supply resumption step. The substrate processing method according to any one of claims 1 to 13, further comprising a dry etching process for performing a dry etching process on the first main surface of the substrate before the etching liquid supply process. 1. A substrate processing apparatus for processing a substrate having a first main surface and a second main surface opposite to the first main surface,
an etching treatment liquid supplying member for supplying an etching treatment liquid containing an etching component and a gelling agent to the first main surface;
a cooling member that cools the second main surface to a temperature equal to or lower than the freezing point of the gelling agent;
a rinse liquid supplying member that supplies a rinse liquid having a temperature equal to or higher than a melting point of the gelling agent to the first main surface. the cooling member cools the substrate with the etching treatment liquid adhering to the first main surface,
The substrate processing apparatus according to claim 15 , wherein the rinsing liquid supplying member supplies the rinsing liquid to the first main surface of the substrate in a state cooled by the cooling member. The substrate processing apparatus according to claim 15 or 16, further comprising a heating member that heats the second main surface to a temperature equal to or higher than the melting point. The substrate processing apparatus according to any one of claims 15 to 17, wherein a recess having an opening and a bottom is formed on the first main surface of the substrate. The depth of the recess is 0.5 μm or more and 1.5 μm or less,
The substrate processing apparatus according to claim 18 , wherein the recess has an aspect ratio of 20 or more and 100 or less. The substrate processing apparatus according to claim 15, further comprising a dry processing unit that performs a dry etching process on the first main surface of the substrate.

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