JP7724338B2 - Gas rectifying member for the underside of the substrate - Google Patents

Description

This disclosure relates to a substrate processing apparatus, a substrate processing method, and a computer-readable recording medium.

Patent Document 1 discloses a substrate processing apparatus that performs cleaning and drying processes on the underside of a substrate held by a substrate holding means while rotating the substrate about a vertical axis. The apparatus includes a base member that is positioned opposite the underside of the substrate held by the substrate holding means, a gas outlet that ejects gas into the space between the base member and the underside of the substrate, and a blocking member that is provided to cover the gas outlet.

Japanese Patent Application Publication No. 10-135178

This disclosure describes a substrate processing apparatus, a substrate processing method, and a computer-readable recording medium that can improve the in-plane uniformity of etching processing.

One example of a substrate processing apparatus includes a support unit configured to support a substrate, a base member configured to face the underside of the substrate supported by the support unit while being spaced apart and having a through hole formed therein, a rotation unit configured to rotate the base member and the support unit, a chemical liquid supply unit configured to supply an etching solution to the upper surface of the substrate supported by the support unit, a gas supply unit, and a gas rectification unit configured to rectify the gas supplied from the gas supply unit and discharge the rectified gas into the space between the underside of the substrate supported by the support unit and the base member. The gas rectification unit includes a rod-shaped member extending in the vertical direction, including a tip portion facing the underside of the substrate supported by the support unit and located within the through hole, and an annular rectification member arranged to surround the tip portion. The tip portion includes an annular folded portion provided on the outer peripheral surface so as to protrude outward from the outer peripheral surface of the tip portion and then extend downward. The straightening member includes an annular bottom wall portion whose inner peripheral edge is positioned so as to be spaced apart from the outer peripheral surface of the tip portion; an annular protrusion portion extending upward from the inner peripheral portion of the bottom wall portion so that the tip portion is located between the folded portion and the outer peripheral surface of the tip portion; an annular horizontal straightening portion extending horizontally outward from the folded portion and above the bottom wall portion while being spaced apart from the bottom wall portion; and a plurality of pillar portions connecting the horizontal straightening portion to the bottom wall portion and aligned circumferentially around the tip portion.

The substrate processing apparatus, substrate processing method, and computer-readable recording medium disclosed herein make it possible to improve the in-plane uniformity of the etching process.

FIG. 1 is a diagram schematically illustrating an example of a substrate processing apparatus. FIG. 2 is an enlarged cross-sectional view showing an example of a gas rectifying section and its vicinity. FIG. 3 is a cross-sectional view showing an example of the rectifying member taken along line III-III in FIG. FIG. 4 is a block diagram showing an example of a main part of a substrate processing apparatus. FIG. 5 is a schematic diagram illustrating an example of a hardware configuration of the controller. FIG. 6 is a flowchart illustrating an example of substrate processing. FIG. 7 is a cross-sectional view showing another example of the rectifying member taken along a horizontal plane. FIG. 8 is an enlarged cross-sectional view showing the vicinity of another example of the gas rectifying section.

In the following description, the same elements or elements with the same functions will be designated by the same reference numerals, and duplicate explanations will be omitted. Note that in this specification, when referring to the top, bottom, right, or left of a figure, reference will be made to the orientation of the reference numerals in the figure.

[Substrate processing apparatus]
1 to 3, a description will be given of an example of the configuration of a substrate processing apparatus 1. The substrate processing apparatus 1 is configured to, for example, supply a processing liquid L to the upper surface Wa of a substrate W to perform an etching process on a film F formed on the upper surface Wa of the substrate W. The film F may be composed of a metal film such as titanium nitride, titanium oxide, titanium, tungsten, tantalum, tantalum nitride, aluminum, aluminum oxide, copper, ruthenium, zirconium oxide, or hafnium oxide.

The substrate W may be disk-shaped or may be a non-circular plate shape, such as a polygon. The substrate W may have a cutout portion cut out of a portion. The cutout portion may be, for example, a notch (a U-shaped, V-shaped groove, etc.) or a linear portion extending in a straight line (so-called orientation flat). The substrate W may be, for example, a semiconductor substrate (silicon wafer), a glass substrate, a mask substrate, an FPD (Flat Panel Display) substrate, or any other type of substrate. The diameter of the substrate W may be, for example, approximately 200 mm to 450 mm.

As shown in FIG. 1, the substrate processing apparatus 1 includes a spin holder 10, a gas rectifier 20, a chemical liquid supply unit 30, a rinse liquid supply unit 40, a gas supply unit 50, and a controller Ctr (control unit).

The rotary holder 10 includes a rotary shaft 11 (rotating portion), a drive mechanism 12 (rotating portion), a base member 13, multiple support pins 14 (supporting portion), and multiple gripping mechanisms 15 (supporting portion). The rotary shaft 11 is a hollow tubular member extending vertically. The rotary shaft 11 is configured to be rotatable around a central axis Ax. The drive mechanism 12 is connected to the rotary shaft 11. The drive mechanism 12 operates based on an operating signal from the controller Ctr, and is configured to rotate the rotary shaft 11. The drive mechanism 12 may be a power source such as an electric motor.

The base member 13 is, for example, a flat plate having an annular shape and extending horizontally. That is, a through-hole 13a is formed in the center of the base member 13. The inner periphery of the base member 13 is connected to the tip of the rotating shaft 11. Therefore, the base member 13 is configured to rotate around the central axis Ax of the rotating shaft 11 in conjunction with the rotation of the rotating shaft 11.

The multiple support pins 14 are provided on the base member 13 so as to protrude upward from the upper surface of the base member 13. The number of multiple support pins 14 may be, for example, approximately 3 to 6. The multiple support pins 14 are configured to support the substrate W approximately horizontally by abutting their tips against the underside Wb of the substrate W. The multiple support pins 14 may, for example, have a cylindrical shape or a frustum shape. The multiple support pins 14 may be arranged at approximately equal intervals near the outer periphery of the base member 13 so that they form a circular shape as a whole when viewed from above.

The multiple gripping mechanisms 15 are provided on the base member 13 so as to protrude upward from the base member 13. The number of multiple gripping mechanisms 15 may be, for example, approximately three. The multiple gripping mechanisms 15 are so-called mechanical chucks and are configured to be able to grip the peripheral edge of the substrate W. The multiple gripping mechanisms 15 may be arranged at approximately equal intervals near the outer periphery of the base member 13 so as to form a circular shape as a whole when viewed from above.

When the substrate W is supported by the support pins 14 and the gripping mechanism 15, the substrate W is held above the base member 13 while being spaced apart from the base member 13. In other words, when the substrate W is supported by the support pins 14 and the gripping mechanism 15, the lower surface Wb of the substrate W faces the base member 13.

As described above, the multiple support pins 14 and multiple gripping mechanisms 15 are provided on the base member 13, which is connected to the rotating shaft 11. Therefore, when the drive mechanism 12 drives the rotating shaft 11 to rotate, the base member 13, the multiple support pins 14, and the multiple gripping mechanisms 15 rotate. Therefore, when the drive mechanism 12 drives the rotating shaft 11 to rotate while the substrate W is supported by the multiple support pins 14 and gripped by the multiple gripping mechanisms 15, the substrate W also rotates together with the base member 13, etc.

The gas rectification unit 20 is configured to rectify the gas supplied from the gas supply unit 50 and discharge the rectified gas into the space V between the base member 13 and the underside Wb of the substrate W supported by the support pins 14 and the gripping mechanism 15. As shown in Figures 1 and 2, the gas rectification unit 20 includes a rod-shaped member 100 and a rectification member 200.

The rod-shaped member 100 extends vertically within the rotating shaft 11 and through-hole 13a while being spaced apart from the rotating shaft 11 and through-hole 13a. Therefore, as illustrated in detail in FIG. 2, a gap D is formed between the outer peripheral surface of the rod-shaped member 100 and the inner peripheral surface of the rotating shaft 11. The rod-shaped member 100 may be, for example, columnar or cylindrical. If the rod-shaped member 100 is cylindrical, a rinse liquid, gas, etc. may be supplied from the rod-shaped member 100 toward the underside Wb of the substrate W.

The rod-shaped member 100 includes a tip portion 101 that faces the lower surface Wb of the substrate W supported by the support pins 14 and the gripping mechanism 15 and is positioned within the through-hole 13a. The upper end of the tip portion 101 may be located above the base member 13. The outer peripheral surface of the tip portion 101 is provided with a folded portion 102 that is annular (e.g., circular).

The folded portion 102 protrudes outward from the outer circumferential surface of the tip portion 101 and then extends downward. As a result, the cross section of the folded portion 102 is roughly J-shaped. The combination of the tip portion 101 and the folded portion 102 forms an annular recess with a bottom that is closed at the top and open at the bottom.

The flow straightening member 200 has an overall annular (e.g., circular) shape and is arranged to surround the tip portion 101. In the example shown in Figure 2, the flow straightening member 200 is separate from the rod-shaped member 100 (tip portion 101). As illustrated in Figures 2 and 3, the flow straightening member 200 includes a bottom wall portion 201, a protrusion portion 202, a horizontal flow straightening portion 203, and multiple pillar portions 204.

The bottom wall portion 201 is a plate-like body extending horizontally and has an annular (e.g., circular) shape with a through-hole in the center. The inner peripheral edge of the bottom wall portion 201 is spaced apart from the outer peripheral surface of the tip portion 101. The outer peripheral edge of the bottom wall portion 201 is attached to the through-hole 13a of the base member 13. Therefore, the bottom wall portion 201 is positioned between the tip portion 101 and the base member 13.

The protrusion 202 is a tubular body extending upward from the inner periphery (near the inner edge) of the bottom wall 201. Therefore, the protrusion 202 has an annular (e.g., cylindrical) shape. The tip (upper end) of the protrusion 202 is located in the space (bottomed recess) between the outer periphery of the tip 101 and the inner periphery of the folded portion 102. Therefore, the tip 101, folded portion 102, bottom wall 201, and protrusion 202 form a flow path FL that communicates with gap D. After extending upward from gap D (see arrow Ar1 in FIG. 2), the flow path FL turns approximately 180° and heads downward (see arrow Ar2 in FIG. 2), then changes course approximately 90° toward the gap between the bottom wall 201 and the folded portion 102 (see arrow Ar3 in FIG. 2).

The horizontal rectifier 203 is a plate-like body extending horizontally above the bottom wall 201 and spaced apart from the bottom wall 201, and has an annular (e.g., circular) shape with a through-hole in the center. The horizontal rectifier 203 is located outward from the turning portion 102 in the horizontal direction. Therefore, an annular opening OP that opens upward is formed between the horizontal rectifier 203 and the turning portion 102. Therefore, a portion of the gas discharged from the flow path FL (see arrow Ar3 in Figure 2) forms a vortex at this opening OP (see arrow Ar4 in Figure 2). The distance between the horizontal rectifier 203 and the turning portion 102 may be, for example, approximately 2 mm to 10 mm, or approximately 4 mm to 8 mm.

The multiple pillars 204 extend in the up-down direction (vertical direction) to connect the bottom wall 201 and the horizontal rectification section 203. The number of pillars 204 may be, for example, approximately 3 to 12. The multiple pillars 204 may be arranged circumferentially around the tip 101. In this case, the bottom wall 201, the horizontal rectification section 203, and the multiple pillars 204 form multiple through-holes 204a surrounded by them. Another portion (the portion not forming a vortex) of the gas discharged from the flow path FL (see arrow Ar3 in FIG. 2) is discharged horizontally through the multiple through-holes 204a into the space V between the lower surface Wb of the substrate W and the base member 13 (see arrow Ar5 in FIG. 2).

The multiple pillars 204 may have, for example, a rectangular pillar shape, a cylindrical shape, a frustum shape, or a shape with a recessed central portion in the vertical direction. The multiple pillars 204 may be arranged at approximately equal intervals near the outer periphery of the base member 13 so that they form a circular shape as a whole when viewed from above.

The chemical liquid supply unit 30 is configured to supply an etching liquid L1 to the substrate W. The etching liquid L1 may contain, for example, an alkaline or acidic chemical liquid for removing a film F on the upper surface Wa of the substrate W. The alkaline chemical liquid may contain, for example, an SC-1 liquid (a mixture of ammonia, hydrogen peroxide, and pure water). The acidic chemical liquid may contain, for example, an SC-2 liquid (a mixture of hydrochloric acid, hydrogen peroxide, and pure water), an SPM (a mixture of sulfuric acid and hydrogen peroxide), an HF/ _HNO3 liquid (a mixture of hydrofluoric acid and nitric acid), or the like.

The chemical liquid supply unit 30 includes a liquid source 31, a pump 32, a valve 33, a nozzle 34, a pipe 35, and a drive source 36 (drive unit). The liquid source 31 is a supply source of the etching liquid L1. The pump 32 operates based on an operation signal from the controller Ctr, and is configured to pump the etching liquid L1 sucked from the liquid source 31 to the nozzle 34 via the pipe 35 and the valve 33.

The valve 33 operates based on an operation signal from the controller Ctr and is configured to transition between an open state that allows the flow of fluid through the piping 35 and a closed state that prevents the flow of fluid through the piping 35. The nozzle 34 is positioned above the substrate W so that its outlet faces the upper surface Wa of the substrate W. The nozzle 34 is configured to eject the etching liquid L1 delivered from the pump 32 from its outlet toward the upper surface Wa of the substrate W.

The pipe 35 connects, in order from the upstream side, the liquid source 31, the pump 32, the valve 33, and the nozzle 34. The drive source 36 is connected directly or indirectly to the nozzle 34. The drive source 36 operates based on an operation signal from the controller Ctr, and is configured to move the nozzle 34 horizontally or vertically above the substrate W.

The rinse liquid supply unit 40 is configured to supply a rinse liquid L2 to the substrate W. The rinse liquid L2 is a liquid for removing (washing away) from the substrate W, for example, the etching liquid L1 supplied to the upper surface Wa of the substrate W and components of the film F dissolved by the etching liquid L1. The rinse liquid L2 may contain, for example, pure water (DIW: deionized water), ozone water, carbonated water ( _CO2 water), ammonia water, etc.

The rinse liquid supply unit 40 includes a liquid source 41, a pump 42, a valve 43, a nozzle 44, a pipe 45, and a drive source 46. The liquid source 41 is a supply source of rinse liquid L2. The pump 42 operates based on an operation signal from the controller Ctr, and is configured to pump rinse liquid L2 sucked from the liquid source 41 to the nozzle 44 via the pipe 45 and the valve 43.

The valve 43 operates based on an operation signal from the controller Ctr and is configured to transition between an open state that allows the flow of fluid through the pipe 45 and a closed state that prevents the flow of fluid through the pipe 45. The nozzle 44 is disposed above the substrate W so that its outlet faces the upper surface Wa of the substrate W. Like the nozzle 34, the nozzle 44 is configured to eject the rinsing liquid L2 delivered from the pump 42 from its outlet toward the upper surface Wa of the substrate W.

The pipe 45 connects, in order from the upstream side, the liquid source 41, the pump 42, the valve 43, and the nozzle 44. The drive source 46 is connected directly or indirectly to the nozzle 44. The drive source 46 operates based on an operation signal from the controller Ctr, and is configured to move the nozzle 44 horizontally or vertically above the substrate W.

The gas supply unit 50 includes a gas source 51, a flow rate regulator 52, and a pipe 53. The gas source 51 stores an inert gas (e.g., nitrogen gas), dry air, or the like, and functions as a gas supply source. The flow rate regulator 52 is provided on the pipe 53 extending from the gas source 51 to the gap D. The flow rate regulator 52 operates based on an operation signal from the controller Ctr, and is configured to open and close the pipe 53 and adjust the opening degree.

As shown in Figure 4, the controller Ctr has the following functional modules: a reading unit M1, a memory unit M2, a processing unit M3, and an instruction unit M4. These functional modules are merely a convenient division of the functions of the controller Ctr into multiple modules, and do not necessarily mean that the hardware that makes up the controller Ctr is divided into such modules. Each functional module is not limited to being realized by executing a program, but may also be realized by a dedicated electrical circuit (e.g., a logic circuit) or an integrated circuit (ASIC: Application Specific Integrated Circuit) that integrates such a circuit.

The reading unit M1 is configured to read a program from a computer-readable recording medium RM. The recording medium RM stores a program for operating each part of the substrate processing apparatus 1. The recording medium RM may be, for example, a semiconductor memory, an optical recording disk, a magnetic recording disk, or a magneto-optical recording disk. Note that, hereinafter, each part of the substrate processing apparatus 1 may include a spin holder 10, a chemical liquid supply unit 30, a rinse liquid supply unit 40, a gas supply unit 50, etc.

Memory unit M2 is configured to store various data. For example, memory unit M2 may store programs read from recording medium RM by reading unit M1, setting data input by an operator via an external input device (not shown), and the like.

Processing unit M3 is configured to process various types of data. Processing unit M3 may be configured to generate operation signals for operating each unit of the substrate processing apparatus 1, for example, based on the various types of data stored in memory unit M2.

The instruction unit M4 is configured to transmit the operation signals generated in the processing unit M3 to each part of the substrate processing apparatus 1.

The hardware of the controller Ctr may be configured, for example, by one or more control computers. As shown in FIG. 5, the controller Ctr may include a circuit C1 as a hardware configuration. The circuit C1 may be configured with electrical circuitry. The circuit C1 may include, for example, a processor C2, a memory C3, a storage C4, a driver C5, and an input/output port C6.

The processor C2 may be configured to execute programs in cooperation with at least one of the memory C3 and storage C4 and to implement each of the functional modules described above by inputting and outputting signals via the input/output port C6. The memory C3 and storage C4 may function as the memory unit M2. The driver C5 may be a circuit configured to drive each component of the substrate processing apparatus 1. The input/output port C6 may be configured to mediate the input and output of signals between the driver C5 and each component of the substrate processing apparatus 1.

The substrate processing apparatus 1 may include a single controller Ctr, or a controller group (controller) composed of multiple controllers Ctr. If the substrate processing apparatus 1 includes a controller group, each of the above-mentioned functional modules may be implemented by a single controller Ctr, or by a combination of two or more controllers Ctr. If the controller Ctr is composed of multiple computers (circuits C1), each of the above-mentioned functional modules may be implemented by a single computer (circuit C1) or by a combination of two or more computers (circuits C1). The controller Ctr may include multiple processors C2. In this case, each of the above-mentioned functional modules may be implemented by a single processor C2, or by a combination of two or more processors C2.

[Substrate processing method]
Next, a method for etching a film F formed on the upper surface Wa of a substrate W using the substrate processing apparatus 1 (substrate processing method) will be described with reference to FIG.

First, a transport mechanism (not shown) places the substrate W on the support pins 14. In this state, the controller Ctr controls the gripping mechanism 15, which grips the peripheral edge of the substrate W. As a result, the substrate W is supported by the support pins 14 and the gripping mechanism 15 (see step S11 in Figure 6).

Next, the controller Ctr controls the drive mechanism 12 to rotate the rotating shaft 11 at a predetermined rotation speed. At this time, the substrate W also rotates along with the rotating shaft 11, base member 13, support pins 14, and gripping mechanism 15 (see step S12 in Figure 6).

Next, the controller Ctr controls the chemical liquid supply unit 30 to supply the etching liquid L1 toward the upper surface Wa of the rotating substrate W (see step S13 in Figure 6). As a result, the etching liquid L1 flows along the upper surface Wa toward the outer periphery of the substrate W due to centrifugal force, and is then thrown outward from the outer periphery of the substrate W. As a result, the etching process of the film F formed on the upper surface Wa of the substrate W progresses.

During the supply of the etching liquid L1, the controller Ctr also controls the gas supply unit 50 to supply gas from the gas rectifying unit 20 (rectifying member 200) through the gap D and the flow path FL to the space V between the underside Wb of the substrate W and the base member 13. As illustrated in FIG. 2, the gas flows from the gap D into the flow path FL (see arrow Ar1 in FIG. 2), turns approximately 180 degrees (see arrow Ar2 in FIG. 2), and then changes direction by approximately 90 degrees (see arrow Ar3 in FIG. 2). A portion of the gas then forms a vortex at the opening OP (see arrow Ar4 in FIG. 2). Meanwhile, another portion of the gas is discharged horizontally through the multiple through-holes 204a toward the space V between the underside Wb of the substrate W and the base member 13 (see arrow Ar5 in FIG. 2), and flows all the way to the outer periphery of the substrate W.

Next, the controller Ctr controls the rinse liquid supply unit 40 to supply rinse liquid L2 toward the upper surface Wa of the rotating substrate W (see step S14 in Figure 6). As a result, the rinse liquid L2 flows along the upper surface Wa toward the outer periphery of the substrate W due to centrifugal force, and is then thrown outward from the outer periphery of the substrate W. As a result, the etching liquid L1 and dissolved film F are washed away from the upper surface Wa of the substrate W. At this time, the controller Ctr may also control the gas supply unit 50 to supply gas from the gas rectification unit 20 (rectification member 200) to the space V.

Next, the controller Ctr controls the drive mechanism 12 to maintain the rotation of the substrate W. This causes the rinse liquid L2 to be shaken off from the substrate W, and the substrate W is dried (see step S15 in Figure 6). This completes the processing of the substrate W. Note that, in order to prevent the occurrence of watermarks, etc., after the rinse liquid L2 is supplied to the substrate W, an organic solvent (e.g., isopropyl alcohol) may be supplied to the upper surface Wa of the substrate W, and then the substrate W may be dried.

[Effect]
According to the above example, the other portion of the gas is discharged through the multiple through holes 204a in the horizontal direction toward the space V between the lower surface Wb of the substrate W and the base member 13 (see arrow Ar5 in FIG. 2). That is, the other portion of the gas changes direction multiple times, making it easier for the gas to flow primarily in the horizontal direction. This makes it more difficult for the gas to flow toward the lower surface Wb of the substrate W, making it more difficult for the substrate W to be locally cooled by the gas. As a result, it is possible to improve the in-plane uniformity of the etching process.

In the above example, a portion of the gas forms a vortex at the opening OP. This causes the gas to flow in the portion of the space V between the underside Wb of the substrate W and the base member 13 above the flow straightening member 200, thereby supplying the gas over a wide area of the space V. This makes it possible to improve the in-surface uniformity of the etching process while suppressing adhesion of foreign matter to the underside Wb of the substrate W and intrusion of the etching liquid onto the underside Wb of the substrate W.

In the above example, the horizontal distance between the turning portion 102 and the horizontal rectifying portion 203 can be set to approximately 2 mm to 10 mm. If the distance is 2 mm or more, gas is less likely to be ejected upward from the opening OP, and gas vortices tend to form more easily at the opening OP. If the distance is 10 mm or less, gas vortices formed at the opening OP are less likely to expand in diameter, and partial cooling of the substrate W due to vortices tends to be suppressed.

In the above example, the through hole 13a is provided in the center of the base member 13, and the outer periphery of the bottom wall portion 201 is connected to the through hole 13a. Therefore, the rectifying member 200 rotates together with the base member 13, support pins 14, gripping mechanism 15, and substrate W. In other words, the rectifying member 200 is stationary relative to the substrate W. As a result, gas blown from the gas rectifying unit 20 into the space V between the underside Wb of the substrate W and the base member 13 tends to flow radially on the underside Wb of the substrate W. This makes it possible to further suppress adhesion of foreign matter to the underside Wb of the substrate W.

[Modification]
The disclosure in this specification should be considered to be illustrative in all respects and not restrictive. Various omissions, substitutions, modifications, etc. may be made to the above examples without departing from the scope and spirit of the claims.

(1) The through hole 13a may be located eccentrically from the center of the base member 13.

(2) The outer periphery of the bottom wall portion 201 may not be connected to the through-hole 13a, and the inner periphery of the bottom wall portion 201 may be connected to the rod-shaped member 100. In other words, the flow straightening member 200 does not have to rotate.

(3) As illustrated in FIG. 7 , the multiple pillar portions 204 may extend obliquely with respect to both the circumferential direction and the radial direction of the rotation axis of the straightening member 200, as viewed from the direction of the rotation axis. In this case, the multiple pillar portions 204 straighten the gas, making it easier for the gas to be discharged into the space V between the underside Wb of the substrate W and the base member 13. This makes it possible to further suppress adhesion of foreign matter to the underside Wb of the substrate W. The pillar portions 204 may be wing-shaped, as in the example shown in FIG. 7 , or may be flat. In other words, the straightening member 200 may have a structure similar to a sirocco fan or a turbo fan.

(4) As illustrated in FIG. 8, the straightening member 200 may further include an annular cover portion 205 provided on one of the folded portion 102 and the horizontal straightening portion 203 so as to be positioned between them. In this case, the size of the opening OP can be adjusted by the cover portion 205. In other words, it is possible to adjust the diameter of the vortex formed at the opening OP. The cover portion 205 may be configured to be detachable from one of the folded portion 102 and the horizontal straightening portion 203, or may be fixedly attached.

(5) In step S13 of FIG. 6 , the controller Ctr may control the gas supply unit 50 to adjust the amount of gas supplied from the gas supply unit 50 depending on the position at which the etching liquid L1 is discharged onto the substrate W. Specifically, the drive source 36 and the gas supply unit 50 may be controlled so that the amount of gas supplied from the gas supply unit 50 when the etching liquid L1 is discharged from the nozzle 34 onto the central portion of the substrate W is less than the amount of gas supplied from the gas supply unit 50 when the etching liquid L1 is discharged from the nozzle 34 onto the outer periphery of the substrate W. In this case, the amount of gas supplied when the central portion of the substrate W is being etched is relatively less, so the degree of progress of the etching process becomes closer near the center and at the outer periphery of the substrate W. This makes it possible to further improve the in-plane uniformity of the etching process. Note that the "central portion" of the substrate W may be, for example, a radius from the center of the substrate W ranging from 60 mm to 90 mm.

(6) In step S13 of FIG. 6, the controller Ctr may control the chemical liquid supply unit 30 to supply the etching liquid L1 between the vicinity of the center of the substrate W and the peripheral edge of the substrate while moving the nozzle 34 back and forth. In this case, the etching liquid L1 is more likely to be supplied uniformly over the entire substrate. This makes it possible to improve the in-plane uniformity of the etching process.

(7) In step S13 of FIG. 6 , the controller Ctr may control the chemical liquid supply unit 30 to set the movement speed of the nozzle 34 when ejecting the etching liquid L1 from the nozzle 34 onto the central portion of the substrate W to 150 mm/sec or less. In this case, compared to a typical processing recipe, the movement speed of the nozzle 34 when etching the central portion of the substrate W is relatively slow, and therefore the central portion of the substrate W is etched for a relatively long time. As a result, the degree of progress of the etching process becomes similar near the center and at the outer periphery of the substrate W. This makes it possible to further improve the in-plane uniformity of the etching process.

(8) In step S13 of FIG. 6 , the controller Ctr may control the gas supply unit 50 to adjust the amount of gas supplied to the gas rectification unit 20 in accordance with the rotation speed of the substrate W. In this case, for example, the amount of gas supplied to the gas rectification unit 20 is set to decrease as the rotation speed of the substrate W decreases. When the rotation speed of the substrate W is low, the negative pressure generated in the space V between the lower surface Wb of the substrate W and the base member 13 decreases, making it difficult for foreign matter to be sucked into the space V. Therefore, even if the amount of gas supplied to the gas rectification unit 20 is small, adhesion of foreign matter to the lower surface Wb of the substrate W tends to be suppressed. Moreover, when the amount of gas supplied to the gas rectification unit 20 is low, the substrate W is less likely to be cooled by the gas. Therefore, the in-plane uniformity of the etching process also tends to increase. For example, when the rotation speed of the substrate W is approximately 250 rpm, the amount of gas supplied to the gas rectification unit 20 may be approximately 20 m/min. When the rotation speed of the substrate W is approximately 1000 rpm, the gas supply rate to the gas rectification unit 20 may be approximately 40 m/min. In other words, there may be an exponential correspondence between the rotation speed of the substrate W and the gas supply rate.

[Other examples]
Example 1. An example of a substrate processing apparatus includes a support configured to support a substrate having a film formed on its upper surface, a base member configured to face the underside of the substrate supported on the support member while being spaced apart from the underside and having a through hole formed therein, a rotation unit configured to rotate the base member and the support member, a chemical solution supply unit configured to supply an etching solution to the upper surface of the substrate supported on the support member, a gas supply unit, and a gas rectification unit configured to rectify the gas supplied from the gas supply unit and discharge the rectified gas into a space between the underside of the substrate supported on the support member and the base member. The gas rectification unit includes a rod-shaped member extending in the vertical direction, including a tip portion facing the underside of the substrate supported on the support member and located within the through hole, and an annular rectification member arranged to surround the tip portion. The tip portion includes an annular folded portion provided on the outer circumferential surface so as to protrude outward from the outer circumferential surface of the tip portion and then extend downward. The straightening member includes an annular bottom wall portion whose inner peripheral edge is positioned so as to be spaced apart from the outer peripheral surface of the tip portion; an annular protrusion portion extending upward from the inner peripheral portion of the bottom wall portion so that the tip portion is located between the folded portion and the outer peripheral surface of the tip portion; an annular horizontal straightening portion extending horizontally outward from the folded portion and above the bottom wall portion while being spaced apart from the bottom wall portion; and a plurality of pillar portions connecting the horizontal straightening portion and the bottom wall portion and aligned circumferentially of the tip portion.

During etching, gas is sometimes supplied to the space between the underside of the substrate and the base member to prevent foreign matter from adhering to the underside of the substrate and to prevent the etching solution from wrapping around the edges of the substrate and adhering to the underside. In this case, if gas is supplied to the space between the underside of the substrate and the base member without the above-mentioned straightening member, uneven airflow may occur on the underside of the substrate due to factors such as the precision of the machining process of the device. If etching solution is supplied to the top surface of the substrate in this state to etch the film on the top surface of the substrate, unevenness in the progress of the chemical reaction of the etching solution may also occur, which may affect the uniformity of the film thickness after etching across the surface of the substrate.

However, in Example 1, the gas supplied from the gas supply unit to the gas rectifying unit passes through the gap between the outer peripheral surface of the tip and the protruding portion, then changes direction, passes through the gap between the protruding portion and the folded portion, and then changes direction again to the horizontal direction. As a result, some of the gas that has changed direction horizontally passes through the gap between the horizontal rectifying unit and the bottom wall, and is then discharged into the space between the underside of the substrate and the base member. Therefore, by changing direction multiple times, the gas discharged from the gas rectifying unit tends to flow primarily horizontally. This makes it more difficult for the gas to flow toward the underside of the substrate, making it less likely for the substrate to be locally cooled by the gas. As a result, it is possible to improve the in-plane uniformity of the etching process.

In addition, in Example 1, the horizontal rectifier section is located outward from the folded section. Therefore, the gas rectifier section has an annular opening that opens upward between the horizontal rectifier section and the folded section. Therefore, another portion of the gas that has been redirected horizontally forms a vortex at this opening. As a result, gas also flows in the portion of the space between the underside of the substrate and the base member above the rectifier section, and gas is supplied over a wide area of that space. Therefore, it is possible to improve the in-plane uniformity of the etching process while suppressing the adhesion of foreign matter to the underside of the substrate and the intrusion of the etching solution onto the underside of the substrate.

Example 2. In the apparatus of Example 1, the horizontal separation distance between the folding portion and the horizontal rectifying portion may be 2 mm to 10 mm. If the separation distance is 2 mm or more, gas is less likely to be ejected upward from the opening of the gas rectifying portion, and a gas vortex tends to form more easily at the opening of the gas rectifying portion. If the separation distance is 10 mm or less, the gas vortex formed at the opening of the gas rectifying portion is less likely to expand in diameter, and partial cooling of the substrate due to the vortex tends to be suppressed.

Example 3. In the device of Example 1 or Example 2, the rectifying member may further include an annular cover portion provided on one of the folded portion and the horizontal rectifying portion so as to be positioned between them. In this case, the size of the opening of the gas rectifying portion can be adjusted by the cover portion.

Example 4. In any of the devices of Examples 1 to 3, the through hole may be provided in the center of the base member, and the outer periphery of the bottom wall portion may be connected to the through hole. In this case, the rectifying member rotates together with the base member, the support portion, and the substrate. In other words, the rectifying member is stationary relative to the substrate. As a result, gas blown from the gas rectifying portion into the space between the underside of the substrate and the base member tends to flow radially on the underside of the substrate. This makes it possible to further suppress the adhesion of foreign matter to the underside of the substrate.

Example 5. In the device of Example 4, the multiple pillars may extend obliquely with respect to both the circumferential direction and the radial direction of the rotation axis when viewed from the direction of the rotation axis of the straightening member. In this case, the multiple pillars straighten the gas, making it easier for the gas to be discharged into the space between the underside of the substrate and the base member. This makes it possible to further suppress the adhesion of foreign matter to the underside of the substrate.

Example 6. The apparatus of any of Examples 1 to 5 may further include a control unit, wherein the chemical liquid supply unit includes a nozzle configured to discharge an etching solution and a drive unit configured to move the nozzle horizontally above the substrate supported by the support unit. The control unit may be configured to control the drive unit and the gas supply unit to execute a process of adjusting the amount of gas supplied from the gas supply unit in accordance with the position at which the etching solution is discharged onto the substrate, so that the amount of gas supplied to the gas rectification unit when the etching solution is discharged from the nozzle onto the central portion of the substrate is less than the amount of gas supplied to the gas rectification unit when the etching solution is discharged from the nozzle onto the peripheral portion of the substrate. However, there may be a difference between the degree to which the central portion of the substrate is cooled by the vortex generated at the opening of the gas rectification unit and the degree to which the peripheral portion of the substrate is cooled by the gas blown out from the gap between the horizontal rectification unit and the bottom wall. However, according to Example 7, the amount of gas supplied when the central portion of the substrate is being etched is relatively small, so the degree of progress of the etching process becomes closer between the central portion of the substrate and the peripheral portion. This makes it possible to further improve the in-plane uniformity of the etching process.

Example 7. In the apparatus of Example 6, the central portion may have a radius from the center of the substrate in the range of 60 mm to 90 mm.

Example 8. In the apparatus of Example 6 or Example 7, the control unit may be configured to control the drive unit to reciprocate the nozzle, thereby supplying the etching liquid to the area between the center of the substrate and the peripheral edge of the substrate. In this case, the etching liquid is more likely to be supplied uniformly across the entire substrate. This makes it possible to improve the in-plane uniformity of the etching process.

Example 9. In any of the devices of Examples 6 to 8, the control unit may be configured to control the drive unit to execute a process in which the nozzle movement speed when ejecting etching solution from the nozzle onto the central portion of the substrate is 150 mm/sec or less. As noted in Example 6, there may be a difference between the degree to which the central portion of the substrate is cooled and the degree to which the peripheral portion of the substrate is cooled. However, according to Example 9, the nozzle movement speed is relatively slow when the central portion of the substrate is being etched, so the central portion of the substrate is etched for a relatively long time. As a result, the rate of progress of the etching process becomes similar near the central portion of the substrate and at the peripheral portion. This makes it possible to further improve the in-plane uniformity of the etching process.

Example 10. In the apparatus of any of Examples 6 to 9, the control unit may be configured to control the gas supply unit to execute a process of adjusting the amount of gas supplied to the gas rectification unit in accordance with the rotation speed of the substrate. In this case, for example, the lower the rotation speed of the substrate, the smaller the amount of gas supplied to the gas rectification unit. When the rotation speed of the substrate is low, the negative pressure generated in the space between the underside of the substrate and the base member is reduced, making it difficult for foreign matter to be sucked into that space. Therefore, even if the amount of gas supplied to the gas rectification unit is small, adhesion of foreign matter to the underside of the substrate tends to be suppressed. Moreover, when the amount of gas supplied to the gas rectification unit is small, the substrate is less likely to be cooled by the gas. Therefore, the in-plane uniformity of the etching process also tends to be improved.

Example 11. One example of a substrate processing method includes a first step of supporting a substrate with a support member so that the underside of the substrate, on whose upper surface a film is formed, faces a base member while being spaced apart; a second step of rotating the substrate by rotating the base member and the support member; and a third step of supplying an etching solution to the upper surface of the rotating substrate while supplying gas to the gas rectifier member, thereby discharging the gas rectified by the gas rectifier member into the space between the underside of the substrate, on whose upper surface the etching solution has been supplied, and the base member. The gas rectifier member includes a rod-shaped member extending in the vertical direction, including a tip portion that faces the underside of the substrate supported by the support member and is located within a through-hole provided in the base member, and an annular rectifier member arranged to surround the tip portion. The tip portion includes an annular folded portion provided on the outer circumferential surface so as to protrude outward from the outer circumferential surface of the tip portion and then extend downward. The straightening member includes an annular bottom wall portion whose inner peripheral edge is positioned so as to be spaced apart from the outer peripheral surface of the tip portion; an annular protrusion portion extending upward from the inner peripheral portion of the bottom wall portion so that the tip portion is located between the folded portion and the outer peripheral surface of the tip portion; an annular horizontal straightening portion extending horizontally outward from the folded portion and above the bottom wall portion while being spaced apart from the bottom wall portion; and a plurality of pillar portions connecting the horizontal straightening portion to the bottom wall portion and aligned along the circumferential direction of the tip portion. In this case, the same effects as those of the device in Example 1 can be obtained.

Example 12. In the method of Example 11, the horizontal separation distance between the folding portion and the horizontal rectifying portion may be 2 mm to 10 mm. In this case, the same effects as those of the device of Example 2 can be obtained.

Example 13. In the method of Example 11 or Example 12, the straightening member may further include an annular cover portion provided on one of the folded portion and the horizontal straightening portion so as to be positioned between them. In this case, the same effects as those of the device of Example 3 can be obtained.

Example 14. In any of the methods of Examples 11 to 13, the through hole may be provided in the center of the base member, and the outer periphery of the bottom wall portion may be connected to the through hole. In this case, the same effects as those of the device of Example 4 can be obtained.

Example 15. In the method of Example 14, the multiple pillars may extend obliquely with respect to both the circumferential direction and the radial direction of the rotational axis when viewed from the direction of the rotational axis of the straightening member. In this case, the same effects as those of the device of Example 5 can be obtained.

Example 16. In any of the methods of Examples 11 to 15, the third step may include reducing the amount of gas supplied to the gas rectification unit when the etching solution is discharged from the nozzle onto the central portion of the substrate compared to the amount of gas supplied to the gas rectification unit when the etching solution is discharged from the nozzle onto the peripheral portion of the substrate. In this case, the same effects as those of the device of Example 6 can be obtained.

Example 17. In the method of Example 16, the central portion may have a radius from the center of the substrate ranging from 60 mm to 90 mm.

Example 18. In the method of Example 16 or Example 17, the third step may include supplying the etching liquid to the area between the vicinity of the center of the substrate and the peripheral edge of the substrate by moving the nozzle back and forth. In this case, the same effects as those of the apparatus of Example 8 can be obtained.

Example 19. In any of the methods of Examples 16 to 18, the third step may include setting the nozzle movement speed when ejecting the etching solution from the nozzle onto the center of the substrate to 150 mm/sec or less. In this case, the same effects as those of the device of Example 9 can be obtained.

Example 20. In any of the methods of Examples 16 to 19, the third step may include adjusting the amount of gas supplied to the gas rectification unit in accordance with the rotation speed of the substrate. In this case, the same effects as those of the apparatus of Example 10 can be obtained.

Example 21. An example of a computer-readable recording medium may have a program recorded thereon for causing a substrate processing apparatus to execute any of the methods of Examples 11 to 20. In this case, the same effects as those of the apparatus of Example 1 can be obtained. In this specification, a computer-readable recording medium may include a non-transitory computer recording medium (e.g., various primary or secondary storage devices) or a propagated signal (e.g., a data signal that can be provided via a network).

1...substrate processing apparatus, 10...rotational holding unit, 11...rotation shaft (rotating unit), 12...drive mechanism (rotating unit), 13...base member, 13a...through hole, 14...support pin (supporting unit), 15...gripping mechanism (supporting unit), 20...gas rectifying unit, 30...chemical liquid supply unit, 34...nozzle, 36...drive source (driving unit), 50...gas supply unit, 100...rod-shaped member, 101...tip portion, 102...folded portion, 200...rectifying member, 201...bottom wall portion, 202...protruding portion, 203...horizontal rectifying unit, 204...pillar portion, 205...cover portion, Ctr...controller (control unit), D...gap, F...film, FL...flow path, L1...etchant, OP...opening, RM...recording medium, V...space, W...substrate, Wa...upper surface, Wb...lower surface.

Claims (6)

An annular gas rectifying member for rectifying a gas supplied to a lower surface of a substrate,
an annular bottom wall portion;
an annular protrusion extending upward from an inner periphery of the bottom wall;
an annular horizontal straightening portion that is above the bottom wall portion and extends outward from the bottom wall portion along the horizontal direction while being spaced apart from the bottom wall portion ;
a gas rectifying member including a plurality of pillars that connect an inner peripheral portion of the horizontal rectifying portion and an outer peripheral portion of the bottom wall portion and are arranged in a circumferential direction of a central axis of the gas rectifying member; The gas rectifying member according to claim 1 , wherein the plurality of pillar portions extend obliquely with respect to both the circumferential direction and the radial direction of the central axis when viewed from the extending direction of the central axis. 3. The gas rectifying member according to claim 1, wherein an inner circumferential portion of the horizontal rectifying portion is spaced apart from the tip of the protrusion in the horizontal direction, thereby forming an opening between the inner circumferential portion of the horizontal rectifying portion and the tip of the protrusion. A gas rectifying member as described in any one of claims 1 to 3, wherein when positioned below the lower surface of the substrate, the bottom wall portion is positioned so that the inner peripheral edge of the bottom wall portion surrounds the center of the substrate when viewed from the extension direction of the central axis. The gas rectifying member according to any one of claims 1 to 4, wherein the plurality of column portions are arranged at approximately equal intervals in the circumferential direction of the central axis so as to form a circular shape as a whole when viewed in the direction of extension of the central axis. The gas rectifying member according to any one of claims 1 to 5, further comprising a cover member provided on an inner circumferential portion of the horizontal rectifying portion so as to extend radially inward from the inner circumferential portion of the horizontal rectifying portion.