JP7486601B2 - SUBSTRATE PROCESSING METHOD AND SUBSTRATE PROCESSING APPARATUS - Google Patents

Description

The disclosed embodiments relate to a substrate processing method and a substrate processing apparatus.

Conventionally, a technology has been known in which an alkaline processing liquid is supplied to a substrate to perform an etching process (see Patent Document 1).

JP 2019-12802 A

The present disclosure provides a technology that can improve the uniformity of the etching amount in the depth direction of a hole formed in a substrate.

A substrate processing method according to one aspect of the present disclosure includes a holding step, an immersion step, and a pressurization step. The holding step holds the substrate horizontally in a sealable processing space. The immersion step supplies a processing liquid into the processing space to immerse the substrate in the processing liquid. The pressurization step pressurizes the processing space to a pressure higher than atmospheric pressure.

According to the present disclosure, it is possible to improve the uniformity of the etching amount in the depth direction of a hole formed in a substrate.

FIG. 1 is a schematic diagram showing a schematic configuration of a substrate processing system according to an embodiment. FIG. 2 is a schematic plan view showing a specific configuration example of the processing unit according to the embodiment. FIG. 3 is a schematic cross-sectional view showing a specific configuration example of the processing unit according to the embodiment. FIG. 4 is a diagram for explaining the configuration of the back surface heater according to the embodiment. FIG. 5 is an enlarged cross-sectional view showing a specific configuration example of the processing unit according to the embodiment. FIG. 6 is a diagram showing the relationship between the pressure in the processing space and the etching rate in the etching process according to the embodiment. FIG. 7 is a diagram showing the relationship between the etching rate and the presence or absence of pre-pressurization in the etching process according to the embodiment. FIG. 8 is a flowchart showing a procedure of substrate processing executed by the substrate processing system according to the embodiment.

Below, embodiments of the substrate processing method and substrate processing apparatus disclosed in the present application will be described in detail with reference to the attached drawings. Note that the present disclosure is not limited to the embodiments shown below. It should be noted that the drawings are schematic, and the dimensional relationships and ratios of each element may differ from reality. Furthermore, there may be parts in which the dimensional relationships and ratios differ between the drawings.

A technique has been known in the past in which an alkaline processing liquid is supplied to a substrate to perform an etching process. However, with the above-mentioned conventional technique, there were cases in which the difference between the amount of etching at the opening side of a hole formed in the substrate and the amount of etching at the bottom side of the hole was large.

Therefore, it is hoped that technology can be developed that can overcome the above-mentioned problems and improve the uniformity of the etching amount in the depth direction of holes formed in a substrate.

<Overview of the Substrate Processing System>
First, a schematic configuration of a substrate processing system 1 according to an embodiment will be described with reference to Fig. 1. Fig. 1 is a diagram showing a schematic configuration of the substrate processing system 1 according to an embodiment. The substrate processing system 1 is an example of a substrate processing apparatus. In the following, in order to clarify the positional relationship, an X-axis, a Y-axis, and a Z-axis that are orthogonal to each other are defined, and the positive direction of the Z-axis is defined as a vertically upward direction.

As shown in Figure 1, the substrate processing system 1 includes a loading/unloading station 2 and a processing station 3. The loading/unloading station 2 and the processing station 3 are provided adjacent to each other.

The loading/unloading station 2 includes a carrier placement section 11 and a transport section 12. A plurality of carriers C are placed on the carrier placement section 11, each of which accommodates a plurality of substrates, in this embodiment, semiconductor wafers W (hereinafter referred to as wafers W), in a horizontal position.

The transfer section 12 is provided adjacent to the carrier placement section 11, and includes a substrate transfer device 13 and a transfer section 14. The substrate transfer device 13 includes a wafer holding mechanism that holds the wafer W. The substrate transfer device 13 is capable of moving horizontally and vertically and rotating about a vertical axis, and transfers the wafer W between the carrier C and the transfer section 14 using the wafer holding mechanism.

The processing station 3 is provided adjacent to the transport section 12. The processing station 3 includes a transport section 15 and a plurality of processing units 16. The plurality of processing units 16 are arranged side by side on both sides of the transport section 15.

The transfer section 15 has a substrate transfer device 17 therein. The substrate transfer device 17 has a wafer holding mechanism that holds the wafer W. The substrate transfer device 17 is capable of moving in the horizontal and vertical directions and rotating about a vertical axis, and transfers the wafer W between the delivery section 14 and the processing unit 16 using the wafer holding mechanism.

The processing unit 16 performs a predetermined substrate processing on the wafer W transported by the substrate transport device 17.

The substrate processing system 1 also includes a control device 4. The control device 4 is, for example, a computer, and includes a control unit 18 and a memory unit 19. The memory unit 19 stores programs that control various processes executed in the substrate processing system 1. The control unit 18 controls the operation of the substrate processing system 1 by reading and executing the programs stored in the memory unit 19.

Such a program may be recorded on a computer-readable storage medium and installed from the storage medium into the storage unit 19 of the control device 4. Examples of computer-readable storage media include a hard disk (HD), a flexible disk (FD), a compact disk (CD), a magnetic optical disk (MO), and a memory card.

In the substrate processing system 1 configured as described above, first, the substrate transfer device 13 in the loading/unloading station 2 removes the wafer W from the carrier C placed on the carrier placement section 11, and places the removed wafer W on the transfer section 14. The wafer W placed on the transfer section 14 is removed from the transfer section 14 by the substrate transfer device 17 in the processing station 3, and is transferred to the processing unit 16.

The wafer W carried into the processing unit 16 is processed by the processing unit 16, and then carried out of the processing unit 16 by the substrate transfer device 17 and placed on the transfer section 14. The processed wafer W placed on the transfer section 14 is then returned to the carrier C of the carrier placement section 11 by the substrate transfer device 13.

<Configuration of Processing Unit>
Next, the configuration of the processing unit 16 will be described with reference to Figures 2 to 4. Figure 2 is a schematic plan view showing a specific configuration example of the processing unit 16. As shown in Figure 2, the processing unit 16 includes a chamber 20, a substrate processing section 30, a sealing section 40, a processing liquid supply section 50, and a collection cup 60.

The chamber 20 houses the substrate processing section 30, the sealing section 40, the processing liquid supply section 50, and the collection cup 60. A fan filter unit (FFU) (not shown) is provided in the ceiling of the chamber 20. The FFU creates a downflow within the chamber 20.

The substrate processing unit 30 performs liquid processing on the placed wafer W. Details of the substrate processing unit 30 will be described later.

The sealing section 40 seals the processing space S (see FIG. 3) within the substrate processing section 30. The sealing section 40 has a cover member 41, an arm 42, a swivel lifting mechanism 43, and a rotation mechanism 44. The swivel lifting mechanism 43 is an example of a lifting mechanism.

The lid member 41 is configured to be able to seal the opening 31c (see FIG. 3) of the container member 31 (see FIG. 3). Details of the lid member 41 will be described later.

The arm 42 horizontally supports the cover member 41. The swivel/lift mechanism 43 swivels and lifts the arm 42. The rotation mechanism 44 rotates the cover member 41 at the tip of the arm 42.

The processing liquid supply unit 50 supplies an etching liquid L (see FIG. 3) and a rinsing liquid to the surface of the wafer W. The etching liquid L is an example of a processing liquid.

The processing liquid supply unit 50 includes processing liquid nozzles 51a, 51b, arms 52a, 52b that horizontally support the processing liquid nozzles 51a, 51b, respectively, and pivoting and lifting mechanisms 53a, 53b that pivot and raise and lower the arms 52a, 52b, respectively.

The processing liquid nozzle 51a is connected to an etching liquid supply source via a valve and a flow regulator (not shown). The processing liquid nozzle 51b is connected to a rinsing liquid supply source via a valve and a flow regulator (not shown).

The etching liquid L supplied from the etching liquid supply source is a liquid used in the etching process of the wafer W. The etching liquid L according to the embodiment includes at least one of TMAH (TetraMethylAmmonium Hydroxide), a choline aqueous solution, a KOH (potassium hydroxide) aqueous solution, and ammonia water, for example.

Thus, the etching liquid L in the embodiment is an alkaline etching liquid. The etching liquid L supplied from the etching liquid supply source is ejected from the processing liquid nozzle 51a.

The rinse liquid supplied from the rinse liquid supply source is a liquid used for rinsing the wafer W, such as DIW (DeIonized Water). The rinse liquid supplied from the rinse liquid supply source is ejected from the processing liquid nozzle 51b.

The collection cup 60 is disposed to surround the container member 31 of the substrate processing section 30, and collects the etching liquid L and rinsing liquid that are scattered from the wafer W by the rotation of the container member 31. A drain port (not shown) is formed at the bottom of the collection cup 60, and the etching liquid L and rinsing liquid collected by the collection cup 60 are discharged from the drain port to the outside of the processing unit 16.

In addition, an exhaust port (not shown) is formed at the bottom of the collection cup 60 to discharge the gas supplied from the FFU to the outside of the processing unit 16.

Figure 3 is a schematic cross-sectional view showing a specific configuration example of the processing unit 16 according to the embodiment. As shown in Figure 3, the substrate processing unit 30 has a container member 31, a support member 32, a drive unit 33, a back surface heater 34, and a lift pin 35. The container member 31 also has a substrate holding portion 31a and a dam member 31b.

The substrate holding portion 31a of the container member 31 has a generally circular disk shape and adheres to the bottom surface of the wafer W to hold the wafer W horizontally. The dam member 31b is disposed so as to stand on the entire peripheral portion of the substrate holding portion 31a and blocks the etching solution L supplied to the wafer W on the substrate holding portion 31a.

In this manner, the container member 31 according to the embodiment has an approximately cylindrical portion with an opening 31c formed at the top by the substrate holding portion 31a and the dam member 31b, and with a processing space S formed therein. The wafer W, etching solution L, and the like enter and exit the processing space S via the opening 31c.

The support column 32 is a member extending in the vertical direction, the base end of which is rotatably supported by the drive unit 33, and the tip of which horizontally supports the container member 31. The drive unit 33 rotates the support column 32 around the vertical axis.

The substrate processing unit 30 rotates the support portion 32 using the drive portion 33, thereby rotating the container member 31 supported by the support portion 32, thereby rotating the wafer W held by the substrate holding portion 31a of the container member 31.

The rear surface heater 34 is a planar heater provided on the rear surface (i.e., the lower surface) of the substrate holding portion 31a, and can be made of, for example, a polyimide heater. Figure 4 is a diagram for explaining the configuration of the rear surface heater 34 according to the embodiment. As shown in Figure 4, the rear surface heater 34 has, for example, multiple (e.g., 10) heating zones 34a to 34j.

Each of the heating zones 34a to 34j has a heater element E. The heater element E is composed of a conductor that extends in a serpentine manner inside each of the heating zones 34a to 34j. Note that FIG. 4 shows only the heater element E that is disposed inside the heating zone 34a.

By individually supplying power to the heater elements E arranged in each heating zone 34a to 34J, the different heating zones 34a to 34j of the wafer W can be heated under different conditions. Therefore, according to the embodiment, the temperature distribution of the wafer W can be controlled.

Continuing with the explanation of Figure 3, the lift pins 35 are arranged to penetrate the substrate holding portion 31a and the rear surface heater 34, and are configured to be movable up and down by a lifting mechanism (not shown).

The lift pins 35 support the wafer W when the wafer W is placed on the substrate holder 31a. For example, three lift pins 35 are provided in the substrate processing unit 30 and are arranged at intervals of 120 degrees in the circumferential direction.

A gas nozzle 45 is disposed in the lid member 41 of the sealing portion 40. The outlet of the gas nozzle 45 is exposed on the bottom surface of the lid member 41.

An inert gas supply unit 46 is connected to the gas nozzle 45. The inert gas supply unit 46 supplies an inert gas (such as nitrogen gas or argon gas) to the gas nozzle 45.

The inert gas supply unit 46 has an inert gas supply path 46a, an inert gas supply source 46b, a pump 46c, a flow regulator 46d, and a check valve 46e.

The inert gas supply path 46a connects the inert gas supply source 46b and the gas nozzle 45, and supplies an inert gas (such as nitrogen gas or argon gas) from the inert gas supply source 46b to the gas nozzle 45. In addition, the inert gas supply path 46a is provided with a pump 46c, a flow rate regulator 46d, and a check valve 46e, arranged in this order from the upstream side.

The pump 46c pressurizes the inert gas supplied to the gas nozzle 45 to a pressure higher than atmospheric pressure. The flow regulator 46d adjusts the amount of inert gas supplied to the gas nozzle 45. The flow regulator 46d has an on-off valve, a flow control valve, a flow meter, etc. The check valve 46e prevents gas from flowing back from the gas nozzle 45 to the flow regulator 46d.

In addition, an open passage 46f is connected to the downstream side of the check valve 46e in the inert gas supply passage 46a, and this open passage 46f is connected to the external atmosphere via a flow regulator 46g.

In the processing unit 16 described above, as shown in Fig. 3, the lid member 41 moves above the container member 31 and then moves down to close the opening 31c of the container member 31, thereby sealing the processing space S inside the container member 31. Details of the substrate processing including such a sealing process will be described below with reference to Fig. 5.

<Substrate processing details>
5 is an enlarged cross-sectional view showing a specific configuration example of the processing unit 16 according to the embodiment. As shown in FIG. 5, the cover member 41 has a protruding portion 41a protruding outward from the periphery. An O-ring 41b is disposed on a bottom surface 41a2 of the protruding portion 41a.

In addition, a slit 31b1 is formed in the weir member 31b of the container member 31 at a position corresponding to the protrusion 41a. The upper surface 31b2 of the slit 31b1 has an inclination that lowers in one circumferential direction, and the lower surface 31b3 of the slit 31b1 is approximately horizontal.

Here, as a procedure for substrate processing according to the embodiment, first, a wafer W is placed in the processing space S inside the container member 31, as shown in Figure 5. Next, an etching liquid L is supplied to the processing space S using a processing liquid nozzle 51a (see Figure 2). Then, the swivel lift mechanism 43 (see Figure 2) moves the lid member 41 so as to close the opening 31c of the container member 31.

Next, the rotation mechanism 44 (see Figure 2) rotates the cover member 41 along its central axis so that the protrusion 41a of the cover member 41 is inserted into the slit 31b1 of the dam member 31b.

As a result, the upper surface 41a1 of the protrusion 41a moves downward along the upper surface 31b2 of the slit 31b1, and the bottom surface 41a2 of the protrusion 41a is pressed against the lower surface 31b3 of the slit 31b1.

As a result, the O-ring 41b located on the bottom surface 41a2 of the protrusion 41a is pressed against the lower surface 31b3 of the slit 31b1, and the lid member 41 according to the embodiment can completely seal the processing space S inside the container member 31. That is, in the embodiment, the lid member 41 screws into the container member 31 to completely seal the opening 31c of the container member 31.

Next, the gas nozzle 45 supplies an inert gas to the processing space S sealed by the lid member 41, thereby pressurizing the processing space S to a pressure higher than atmospheric pressure.

In the embodiment, the wafer W is etched with the etching solution L while the processing space S is pressurized to a pressure higher than atmospheric pressure. This improves the etching rate of the polysilicon film formed on the surface of the wafer W.

Figure 6 is a diagram showing the relationship between the pressure in the processing space S and the etching rate in the etching process according to the embodiment. The various conditions for the experimental results shown in Figure 6 were that SC1 (a mixture of ammonia, hydrogen peroxide and water) was used as the etching liquid L, the liquid temperature was 50 (°C), and the immersion time was 600 (seconds). Nitrogen gas was used as the gas for pressurizing the processing space S.

As shown in Figure 6, it can be seen that the etching rate of the polysilicon film is improved by setting the pressure in the processing space S higher than atmospheric pressure (approximately 0.1 MPa).

In the embodiment, the etching rate of the polysilicon film is improved in single-wafer processing, thereby improving the uniformity of the amount of etching in the depth direction of the holes formed in the wafer W. The mechanism behind this is explained below.

When etching wafers W using single-wafer processing, since only one wafer W can be etched at a time, in order to minimize the processing time for each wafer, processing conditions are often used in which the etching solution L is at a high temperature and concentration, resulting in a high etching rate.

On the other hand, when the etching solution L is at a high temperature and concentration, the reaction rate of the etching solution L is greater than the diffusion rate at which the components of the etching solution L diffuse to the bottom of the hole. As a result, the difference between the amount of etching at the opening side of the hole in the wafer W and the amount of etching at the bottom side of the hole in the wafer W becomes large.

In other words, when the etching solution L is at a high temperature and concentration, it is difficult to achieve both a reduction in the processing time for each wafer W and uniformity in the amount of etching in the depth direction of the holes formed in the wafer W.

On the other hand, in the embodiment, the etching rate can be improved by pressurizing the processing space S to a pressure higher than atmospheric pressure. This makes it possible to achieve a high etching rate even under etching conditions where the etching solution L is at a low temperature or concentration and the diffusion rate at which the components of the etching solution L diffuse to the bottom of the hole is greater than the reaction rate of the etching solution L.

That is, in the embodiment, it is possible to achieve both a reduction in the processing time for each wafer W and uniformity in the amount of etching in the depth direction of the holes formed in the wafer W. Therefore, according to the embodiment, it is possible to improve the uniformity in the amount of etching in the depth direction of the holes formed in the wafer W.

In addition, in an embodiment, the processing space S may be pressurized with an inert gas. This reduces the oxygen concentration of the etching solution L in the processing space S, thereby further improving the uniformity of the amount of etching in the depth direction of the hole formed in the wafer W. The mechanism behind this is explained below.

It is known that when an etching process is performed using an alkaline etching solution L, the oxygen contained in the etching solution L is adsorbed onto the wafer W, forming an oxide film.

In the holes formed in the wafer W, the oxygen concentration in the etching solution L is higher on the opening side than on the bottom side, and therefore more oxygen is adsorbed on the opening side than on the bottom side, resulting in a thicker oxide film being formed on the opening side than on the bottom side.

Therefore, when the etching solution L contains a large amount of oxygen, the difference between the amount of etching on the opening side of the hole in the wafer W and the amount of etching on the bottom side of the hole in the wafer W becomes large.

In contrast, in the embodiment, the etching process is performed using an etching solution L with a reduced oxygen concentration. Therefore, in the embodiment, oxygen adsorption on the opening side of the hole in the wafer W is suppressed.

This makes it possible to reduce the difference between the amount of etching at the opening side of the hole in the wafer W and the amount of etching at the bottom side of the hole in the wafer W. Therefore, according to the embodiment, it is possible to further improve the uniformity of the amount of etching in the depth direction of the hole formed in the wafer W.

In addition, in the embodiment, nitrogen gas or argon gas may be used as the inert gas for pressurizing the processing space S. In this way, by using relatively inexpensive gas such as nitrogen gas, the cost of the etching process can be reduced.

Furthermore, according to the embodiment, the processing space S can be efficiently pressurized by screwing the lid member 41 to the container member 31 to completely seal the processing space S and then performing the pressurization process. Therefore, according to the embodiment, the amount of inert gas used can be reduced, and the cost of the etching process can be further reduced.

In addition, in an embodiment, after the processing space S is pressurized to a given pressure, the supply of inert gas from the gas nozzle 45 may be stopped, or the supply of inert gas from the gas nozzle 45 may be continued.

By stopping the supply of inert gas from the gas nozzle 45 after pressurizing the processing space S to a given pressure, the amount of inert gas used can be reduced, thereby further reducing the cost of the etching process.

On the other hand, by continuing to supply inert gas from the gas nozzle 45 after pressurizing the processing space S to a given pressure, the given pressure can be stably maintained, and therefore the etching process can be performed stably.

In addition, in the embodiment, it is preferable that the inert gas pressurized by the pump 46c at a pressure lower than 0.9 (MPa) is supplied into the sealed processing space S. This makes it possible to prevent the cover member 41 from being unexpectedly removed due to the processing space S being pressurized more than necessary. Therefore, according to the embodiment, the etching process can be performed stably.

In addition, in the embodiment, the inert gas supplied to the processing space S is not limited to being pressurized by pump 46c, but inert gas pressurized by factory power supplies, etc. may also be supplied to the processing space S.

In addition, in the embodiment, the etching process may be performed while heating the wafer W and the etching solution L in the processing space S with the backside heater 34. This can further improve the etching rate of the polysilicon film.

In addition, in the embodiment, when the wafer W is being etched in the processing space S, the container member 31 and the lid member 41 may be rotated 180 degrees together. This allows the etching solution L stored in the processing space S to be agitated and the heating distribution by the back surface heater 34 to be made uniform.

Therefore, according to the embodiment, the entire wafer W can be etched evenly.

In addition, the etching process of the embodiment is not limited to the case where the etching solution L is pressurized with an inert gas during the etching process as described above, but the etching solution L may be pressurized with an inert gas before the etching process.

Figure 7 is a diagram showing the relationship between the presence or absence of pre-pressurization and the etching rate in the etching process according to the embodiment. The reference example shown in Figure 7 is an example in which neither pressurization with an inert gas during the etching process (hereinafter also referred to as "pressurization during processing") nor pressurization with an inert gas before the etching process (hereinafter also referred to as "pre-pressurization") is performed.

7, in an embodiment, the etching rate of the polysilicon film can be improved by pre-pressurizing the etching solution L with a pressure higher than atmospheric pressure. This is presumably because the oxygen concentration of the etching solution L in the processing space S can be reduced by pre-pressurizing the etching solution L with an inert gas.

Thus, in the embodiment, the etching rate of the polysilicon film is improved by pre-pressurization, thereby improving the uniformity of the etching amount in the depth direction of the hole formed in the wafer W.

7, the etching rate of the polysilicon film can be further improved by pre-pressurizing the etching solution L and pressurizing it during processing. Therefore, according to the embodiment, the uniformity of the amount of etching in the depth direction of the hole formed in the wafer W can be further improved.

In the example shown in Figure 2, the processing liquid nozzles 51a, 51b are provided separately from the lid member 41, but at least one of the processing liquid nozzles 51a, 51b may be provided in the lid member 41.

In this way, by arranging at least one of the processing liquid nozzles 51a, 51b on the cover member 41, the corresponding arms 52a, 52b and swivel lifting mechanisms 53a, 53b are not required, thereby reducing the manufacturing cost of the processing unit 16.

In addition, by positioning a processing liquid nozzle 51b that ejects rinsing liquid on the cover member 41 and filling the inside of the processing space S with rinsing liquid, the back surface of the cover member 41 can be cleaned with the rinsing liquid.

In addition, in an embodiment, when a processing liquid nozzle 51a for ejecting the etching liquid L is arranged on the lid member 41, after a sealing process for sealing the processing space S with the lid member 41, an immersion process for immersing the wafer W in the etching liquid may be performed.

The substrate processing apparatus (substrate processing system 1) according to the embodiment includes a container member 31, a lid member 41, a gas nozzle 45, a processing liquid nozzle 51a, and a control unit 18. The container member 31 has a substrate holding part 31a that holds the substrate (wafer W) horizontally and a processing space S for processing the substrate (wafer W), and is configured to be rotatable. The lid member 41 is configured to be able to seal the opening 31c of the container member 31. The gas nozzle 45 is provided on the lid member 41 and supplies pressurized gas from the bottom surface of the lid member 41. The processing liquid nozzle 51a supplies processing liquid (etching liquid L) into the container member 31. The control unit 18 holds the substrate (wafer W) with the substrate holding part 31a of the container member 31, and supplies processing liquid (etching liquid L) from the processing liquid nozzle 51a into the processing space S to immerse the substrate (wafer W) in the processing liquid (etching liquid L). Furthermore, the control unit 18 seals the opening 31c of the container member 31 with the lid member 41, and supplies pressurized gas from the gas nozzle 45 to pressurize the inside of the processing space S to a pressure higher than atmospheric pressure. This makes it possible to improve the uniformity of the amount of etching in the depth direction of the hole formed in the wafer W.

In addition, in the substrate processing apparatus (substrate processing system 1) according to the embodiment, the processing liquid nozzle 51a is provided on the cover member 41. This makes it possible to reduce the cost of the processing unit 16.

In addition, in the substrate processing apparatus (substrate processing system 1) according to the embodiment, the lid member 41 is configured to be retractable from the opening 31c of the container member 31 and has a lifting mechanism (swivel lifting mechanism 43). This allows the wafer W to be placed inside the processing space S through the opening 31c of the container member 31.

In addition, in the substrate processing apparatus (substrate processing system 1) according to the embodiment, the cover member 41 has a rotation axis at its center and seals the opening 31c by screwing it into the container member 31. This makes it possible to prevent the inert gas from leaking from the processing space S to the outside during the pressurized processing.

In addition, in the substrate processing apparatus (substrate processing system 1) according to the embodiment, when the lid member 41 seals the opening 31c of the container member 31, the container member 31 and the lid member 41 rotate together by 180 degrees. This allows the entire wafer W to be etched evenly.

<Processing Procedure>
Next, a procedure for substrate processing according to the embodiment will be described with reference to Fig. 8. Fig. 8 is a flow chart showing a procedure for substrate processing executed by the substrate processing system 1 according to the embodiment.

First, the control unit 18 controls the substrate transport devices 13, 17, etc. to transport the wafer W to the processing unit 16, and holds the wafer W horizontally on the substrate holding portion 31a of the processing unit 16 (step S101).

Next, the control unit 18 controls the back surface heater 34 to adjust the temperature of the wafer W to a given temperature (step S102). Then, after the temperature of the wafer W has been adjusted to the given temperature, the control unit 18 controls the substrate holding unit 31a to adsorb the wafer W to the substrate holding unit 31a (step S103).

Next, the control unit 18 controls the processing liquid nozzle 51a to supply the etching liquid L to the processing space S and immerse the wafer W in the processing space S in the etching liquid L (step S104). Then, the control unit 18 controls the sealing unit 40 to seal the processing space S with the lid member 41 (step S105).

Next, the control unit 18 controls the inert gas supply unit 46 to supply an inert gas from the gas nozzle 45 to the processing space S, and pressurizes the processing space S to a pressure higher than atmospheric pressure (step S106). Then, after the processing space S is pressurized to a given pressure, the control unit 18 continues to immerse the wafer W in the etching solution L to etch the wafer W (step S107).

In the process of step S107, the control unit 18 may rotate the container member 31 and the lid member 41 together by 180 degrees. This allows the etching solution L stored in the processing space S to be stirred and the heating distribution by the back surface heater 34 to be made uniform.

Therefore, according to the embodiment, the entire wafer W can be etched evenly.

Then, after a given etching processing time has elapsed, the control unit 18 closes the flow regulator 45d of the inert gas supply path 45a and opens the flow regulator 46g of the open path 46f, thereby opening the processing space S to atmospheric pressure (step S108).

Next, the control unit 18 controls the sealing unit 40 to detach the lid member 41 from the container member 31 (step S109). Then, the control unit 18 controls the substrate processing unit 30 to rotate the container member 31 to shake off the etching solution L stored in the processing space S (step S110).

Next, the control unit 18 controls the processing liquid supply unit 50 and the like to supply a rinsing liquid to the wafer W, thereby rinsing the wafer W (step S111). The control unit 18 then controls the substrate processing unit 30 to dry the wafer W, for example by shaking off the rinsing liquid stored in the processing space S (step S112), thereby completing the series of substrate processing steps.

In addition, in the processing of step S112, the wafer W may be dried by operating the back surface heater 34 to heat the wafer W.

The substrate processing method according to the embodiment includes a holding step (step S101), an immersion step (step S104), and a pressurization step (step S106). The holding step (step S101) holds the substrate (wafer W) horizontally in a sealable processing space S. The immersion step (step S104) supplies a processing liquid (etchant L) into the processing space S to immerse the substrate (wafer W) in the processing liquid (etchant L). The pressurization step (step S106) pressurizes the processing space S to a pressure higher than atmospheric pressure. This improves the uniformity of the amount of etching in the depth direction of the hole formed in the wafer W.

In addition, in the substrate processing method according to the embodiment, the processing liquid (etching liquid L) is an alkaline chemical liquid. This allows the polysilicon film on the surface of the wafer W to be etched.

The substrate processing method according to the embodiment further includes a sealing step (step S105) of sealing the processing space S before the pressurizing step (step S106). The sealing step (step S105) is performed by sealing the opening 31c of the container member 31, which is rotatably configured and has a substrate holding part 31a for holding a substrate (wafer W) and a processing space S, with a lid member 41. This makes it possible to prevent the inert gas from leaking from the processing space S to the outside during the pressurizing process.

In addition, in the substrate processing method according to the embodiment, the pressurization step (step S106) is performed by supplying pressurized gas into the processing space S. This makes it possible to easily pressurize the sealed processing space S.

In addition, in the substrate processing method according to the embodiment, the gas is an inert gas pressurized by pump 46c. This can further improve the uniformity of the amount of etching in the depth direction of the hole formed in the wafer W.

In addition, in the substrate processing method according to the embodiment, the gas is nitrogen gas or argon gas. This can reduce the cost of the etching process.

In addition, in the substrate processing method according to the embodiment, the pressurization step (step S106) continues to supply gas after the processing space S is pressurized to a pressure higher than atmospheric pressure. This allows the etching process to be carried out stably.

In addition, in the substrate processing method according to the embodiment, the pressurization step (step S106) stops the supply of gas after the processing space S is pressurized to a pressure higher than atmospheric pressure. This can further reduce the cost of the etching process.

In addition, in the substrate processing method according to the embodiment, the gas is pressurized at a pressure lower than 0.9 (MPa) and supplied into the processing space S. This allows the etching process to be carried out stably.

Although the embodiments of the present disclosure have been described above, the present disclosure is not limited to the above embodiments, and various modifications are possible without departing from the spirit of the present disclosure. For example, in the above embodiment, an example is shown in which the processing space S is pressurized using an inert gas, but the gas that pressurizes the processing space S is not limited to an inert gas.

Even if the processing space S is pressurized using a gas other than an inert gas, the etching rate of the polysilicon film can be improved by increasing the pressure of the processing space S to a pressure higher than atmospheric pressure.

The disclosed embodiments should be considered in all respects as illustrative and not restrictive. Indeed, the above-described embodiments may be embodied in various forms. Furthermore, the above-described embodiments may be omitted, substituted, or modified in various forms without departing from the scope and spirit of the appended claims.

W Wafer (an example of a substrate)
1. Substrate processing system (an example of a substrate processing apparatus)
16 Processing unit 18 Control unit 30 Substrate processing unit 31 Container member 31a Substrate holding unit 31b Weir member 31c Opening 40 Sealing unit 41 Lid member 43 Swivel lifting mechanism (an example of a lifting mechanism)
45 Gas nozzle 46 Inert gas supply unit 46c Pump 50 Processing liquid supply unit 51a, 51b Processing liquid nozzle L Etching liquid (an example of a processing liquid)
S Processing space

Claims (13)

A method for etching a hole formed in a substrate, comprising: holding the substrate horizontally in a sealable processing space;
an immersion step of supplying a processing liquid , which is an alkaline chemical liquid, into the processing space and immersing the substrate in the processing liquid;
a pressurizing step of pressurizing the inside of the processing space to a pressure higher than atmospheric pressure;
A substrate processing method comprising: The method further includes a sealing step of sealing the processing space before the pressurizing step,
The substrate processing method according to claim 1 , wherein the sealing step is performed by sealing an opening of a rotatable container member having a substrate holding part for holding the substrate and the processing space with a lid member. 3. The substrate processing method according to claim 1 , wherein the pressurizing step is performed by supplying a pressurized gas into the processing space. The method of claim 3 , wherein the gas is an inert gas pressurized by a pump. The substrate processing method according to claim 4 , wherein the gas is nitrogen gas or argon gas. 6. The substrate processing method according to claim 3 , wherein the pressurizing step continues supplying the gas after the processing space has been pressurized to a pressure higher than atmospheric pressure. 6. The substrate processing method according to claim 3 , wherein the pressurizing step stops the supply of the gas after the inside of the processing space is pressurized to a pressure higher than atmospheric pressure. 8. The substrate processing method according to claim 3 , wherein the gas is pressurized at a pressure lower than 0.9 (MPa) and supplied into the processing space. a container member having a substrate holding part for horizontally holding a substrate and a processing space for processing the substrate, the container member being configured to be rotatable;
A cover member configured to seal an opening of the container member;
a gas nozzle provided in the lid member and configured to supply a pressurized gas from a bottom surface of the lid member;
a processing liquid nozzle for supplying a processing liquid , which is an alkaline chemical liquid, into the container member;
A control unit for controlling each unit;
Equipped with
The control unit is
In an etching process for a hole formed in the substrate, the substrate is held by the substrate holding portion of the container member;
supplying the processing liquid from the processing liquid nozzle into the processing space to immerse the substrate in the processing liquid;
The opening of the container member is sealed with the lid member;
The substrate processing apparatus supplies pressurized gas from the gas nozzle to pressurize the processing space to a pressure higher than atmospheric pressure. The substrate processing apparatus according to claim 9 , wherein the processing liquid nozzle is provided on the cover member. The substrate processing apparatus according to claim 9 , wherein the lid member is configured to be retractable from the opening of the container member, and the lid member has a lifting mechanism. The substrate processing apparatus according to claim 9 , wherein the lid member has a rotation axis at its center and is screwed into the container member to seal the opening. 13. The substrate processing apparatus according to claim 9, wherein the container member and the lid member rotate integrally through 180 degrees when the lid member seals the opening of the container member.

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