WO2024014291A1

WO2024014291A1 - Substrate processing method and substrate processing device

Info

Publication number: WO2024014291A1
Application number: PCT/JP2023/023953
Authority: WO
Inventors: 将輝水口; 宏紀櫻井
Original assignee: 東京エレクトロン株式会社
Priority date: 2022-07-12
Filing date: 2023-06-28
Publication date: 2024-01-18

Abstract

This substrate processing method comprises: holding a substrate horizontally and rotating the substrate; supplying, onto a hydrophobic surface of the rotating substrate, a hydrophilizing solution containing a hydrogen peroxide solution or ozone water; and supplying, after the hydrophilizing solution is supplied, a mixed solution of sulfuric acid and hydrogen peroxide solution onto the surface of the rotating substrate.

Description

Substrate processing method and substrate processing apparatus

The present disclosure relates to a substrate processing method and a substrate processing apparatus.

The substrate processing method described in Patent Document 1 processes a substrate using a mixed solution of sulfuric acid and hydrogen peroxide. Sulfuric acid and hydrogen peroxide are supplied to the surface of the substrate from separate nozzles and mixed on the surface of the substrate. The mixed liquid is used for stripping the resist film. After peeling off the resist film, SC1 (a mixed solution of aqueous ammonia and aqueous hydrogen peroxide) is supplied to the surface of the substrate in order to remove sulfur component residue and particles.

Japanese Patent Application Publication No. 2004-288858

One aspect of the present disclosure provides a technique for suppressing the generation of particles on the substrate surface by coating the entire substrate surface with a mixed solution of sulfuric acid and hydrogen peroxide when the substrate surface is hydrophobic.

A substrate processing method according to one embodiment of the present disclosure includes rotating a substrate while holding it horizontally, and supplying a hydrophilic solution containing hydrogen peroxide or ozone water to the hydrophobic surface of the rotating substrate. and, after supplying the hydrophilizing liquid, supplying a mixed solution of sulfuric acid and hydrogen peroxide to the surface of the rotating substrate.

According to one aspect of the present disclosure, when the substrate surface is hydrophobic, the entire substrate surface can be coated with a mixed solution of sulfuric acid and hydrogen peroxide, thereby suppressing the generation of particles on the substrate surface.

FIG. 1 is a sectional view showing a substrate processing apparatus according to one embodiment. FIG. 2 is a plan view showing an example of the first moving section, the second moving section, and the third moving section. FIG. 3 is a flowchart illustrating a substrate processing method according to one embodiment. 4(A) is a diagram showing an example of step S102, FIG. 4(B) is a diagram showing an example of the first stage of step S103, and FIG. 4(C) is a diagram showing an example of the second stage of step S103. FIG. 4D is a diagram showing an example of the first stage of step S104. FIG. 5(A) is a diagram showing an example of the second stage of step S104, FIG. 5(B) is a diagram showing an example of the third stage of step S104, and FIG. 5(C) is a diagram showing an example of step S105. FIG. 5D is a diagram showing an example of step S106. 6(A) is a diagram showing an example of step S107, FIG. 6(B) is a diagram showing an example of step S108, FIG. 6(C) is a diagram showing an example of step S109, and FIG. (D) is a diagram showing an example of step S110. FIG. 7 is a flowchart showing a conventional substrate processing method. FIG. 8 is a perspective view showing an example of step S204.

Hereinafter, embodiments of the present disclosure will be described with reference to the drawings. Note that in each drawing, the same or corresponding configurations are denoted by the same reference numerals, and the description thereof may be omitted. In this specification, the X-axis direction, Y-axis direction, and Z-axis direction are directions perpendicular to each other. The X-axis direction and the Y-axis direction are horizontal, and the Z-axis direction is vertical.

First, a conventional substrate processing method will be described with reference to FIGS. 7 and 8. As shown in FIG. 7, the substrate processing method includes steps S201 to S205. Step S201 includes holding the substrate horizontally and rotating it. While the substrate is being rotated, DHF (dilute hydrofluoric acid) is supplied (step S202), DIW (deionized water) is supplied (step S203), and SPM (sulfuric acid and hydrogen peroxide) is supplied to the substrate surface. Water mixture) is supplied (step S204). Thereafter, the substrate is dried (step S205).

By supplying DHF (step S202) before supplying SPM (step S204), the processing efficiency of the substrate surface by SPM can be improved. However, DHF makes the substrate surface hydrophobic. The longer the DHF supply time, the more hydrophobic the substrate surface becomes.

The hydrophobic substrate surface repels SPM. SPM could not be uniformly wetted and spread, and SPM sometimes scattered finely. Further, the SPM sometimes formed a plurality of spiral arms as shown in FIG. Particles were sometimes generated on the substrate surface because the SPM could not cover the entire substrate surface. Particle generation was noticeable at the outer periphery of the substrate surface.

Although details will be described later, the technology of the present disclosure supplies HPS (hydrogen peroxide solution) after supplying DHF and before supplying SPM. After making the substrate surface hydrophilic by supplying HPS, SPM is supplied. Thereby, the SPM can be uniformly spread over the entire surface of the substrate, and generation of particles on the surface of the substrate can be suppressed.

Furthermore, the technology of the present disclosure starts the supply of HPS after the start of the supply of DIW and before the end of the supply of DIW. In other words, the technology of the present disclosure simultaneously supplies DIW and HPS. By simultaneously supplying DIW and HPS, it is possible to prevent the substrate surface from drying out before the substrate surface becomes sufficiently hydrophilic, and it is possible to suppress the generation of particles.

Further, the technology of the present disclosure replaces the nozzle located at the center position from the nozzle that discharges DIW to the nozzle that discharges HPS between the start of supply of DIW and the end of simultaneous supply of DIW and HPS. While replacing the nozzle, at least one of DIW and HPS is always supplied to the substrate surface. Therefore, drying of the substrate surface can be suppressed, and generation of particles can be suppressed.

Note that after the substrate surface has been made hydrophilic, the supply of the processing liquid may be temporarily interrupted when replacing the nozzle. If the interruption time is short, the substrate surface will not dry out. This is because a hydrophilic substrate surface requires more time for the processing liquid to flow out than a hydrophobic substrate surface.

A substrate processing apparatus 1 according to an embodiment will be described with reference to FIGS. 1 and 2. The substrate processing apparatus 1 processes the surface Wa of the substrate W by supplying a processing liquid to the surface Wa of the substrate W. The substrate processing apparatus 1 uses, for example, DHF, DIW, HPS, SPM, HPS, SC1 (mixture of aqueous ammonia and hydrogen peroxide), and two-fluid (mixture of DIW and gas) as processing liquids. fluid) are supplied to the surface Wa of the substrate W in this order (see FIG. 3).

The substrate processing apparatus 1 includes, for example, a processing container 10, a substrate holding section 20, a substrate rotation section 25, a first supply section 31, a second supply section 32, a third supply section 33, and a fourth supply section. 34, the first nozzle 41, the second nozzle 42, the third nozzle 43, the fourth nozzle 44, the first moving section 51, the second moving section 52, the third moving section 53, and the collecting section 60 and a control section 90.

The processing container 10 accommodates the substrate holding section 20 and the like. A gate 12 and a gate valve 13 for opening and closing the gate 12 are provided on the side wall of the processing container 10 . The substrate W is carried into the processing chamber 10 via the gate 12 by a transport device (not shown). Next, the substrate W is processed with a processing liquid inside the processing container 10. Thereafter, the substrate W is transported to the outside of the processing container 10 via the gate 12 by the transport device.

The substrate holding unit 20 is provided inside the processing container 10 and holds the substrate W horizontally. The substrate holding section 20 has, for example, a claw section 21 that holds the outer peripheral portion of the substrate W. A plurality of claw portions 21 are provided at equal intervals in the circumferential direction of the substrate W. Although not shown, the substrate holder 20 may vacuum suck the lower surface of the substrate W.

The substrate rotating unit 25 rotates the substrate W together with the substrate holding unit 20 by rotating the substrate holding unit 20. The substrate holder 20 holds the substrate W so that the rotation center line of the substrate W and the center of the front surface Wa of the substrate W coincide with each other.

The first supply unit 31 supplies DHF or DIW to the surface Wa of the substrate W via the first nozzle 41. The first supply unit 31 includes, for example, a common line 31a connected to the first nozzle 41, a plurality of individual lines 31b branching from the common line 31a, and a device 31c provided for each individual line 31b. The device 31c includes, for example, an on-off valve, a flow meter, and a flow controller.

The second supply unit 32 supplies DIW or SC1 to the front surface Wa of the substrate W via the second nozzle 42. The second supply unit 32 includes, for example, a common line 32a connected to the second nozzle 42, a plurality of individual lines 32b branching from the common line 32a, and a device 32c provided for each individual line 32b. The device 32c includes, for example, an on-off valve, a flow meter, and a flow controller.

The third supply unit 33 supplies HPS or SPM to the surface Wa of the substrate W via the third nozzle 43. SPM is a mixture of HPS and sulfuric acid. The third supply unit 33 includes, for example, a common line 33a connected to the third nozzle 43, a plurality of individual lines 33b branching from the common line 33a, and a device 33c provided for each individual line 33b. The device 33c includes, for example, an on-off valve, a flow meter, and a flow controller.

The fourth supply unit 34 supplies a mixed fluid of DIW and gas to the surface Wa of the substrate W via the fourth nozzle 44 . The fourth nozzle 44 is a two-fluid nozzle. The fourth supply unit 34 includes, for example, a plurality of individual lines 34b connected to the fourth nozzle 44, and a device 34c provided for each individual line 34b. The device 34c includes, for example, an on-off valve, a flow meter, and a flow controller.

The first moving unit 51 moves the first nozzle 41 in the horizontal and vertical directions. For example, as shown in FIG. 2, the first moving section 51 includes a first arm 51a and a first turning mechanism 51b. The first turning mechanism 51b moves the first nozzle 41 in the horizontal direction by turning the first arm 51a. Further, the first turning mechanism 51b moves the first nozzle 41 in the vertical direction by raising and lowering the first arm 51a. Note that the first moving section 51 may include a guide rail and a linear motion mechanism instead of the first arm 51a and the first turning mechanism 51b. The linear motion mechanism moves the first nozzle 41 horizontally and vertically along the guide rail.

The second moving unit 52 moves the second nozzle 42 in the horizontal and vertical directions independently of the first nozzle 41. For example, as shown in FIG. 2, the second moving section 52 includes a second arm 52a and a second turning mechanism 52b. The second turning mechanism 52b moves the second nozzle 42 in the horizontal direction by turning the second arm 52a. Further, the second turning mechanism 52b moves the second nozzle 42 in the vertical direction by raising and lowering the second arm 52a. In addition, the 2nd moving part 52 may have a guide rail and a linear motion mechanism instead of the 2nd arm 52a and the 2nd rotation mechanism 52b. The linear motion mechanism moves the second nozzle 42 in the horizontal and vertical directions along the guide rail. The second moving unit 52 moves the fourth nozzle 44 together with the second nozzle 42 in the horizontal direction and the vertical direction.

The third moving unit 53 moves the third nozzle 43 in the horizontal and vertical directions independently of the first nozzle 41 and the second nozzle 42. For example, as shown in FIG. 2, the third moving section 53 includes a third arm 53a and a third turning mechanism 53b. The third turning mechanism 53b moves the third nozzle 43 in the horizontal direction by turning the third arm 53a. Further, the third swing mechanism 53b moves the third nozzle 43 in the vertical direction by raising and lowering the third arm 53a. Note that the third moving section 53 may include a guide rail and a linear motion mechanism instead of the third arm 53a and the third turning mechanism 53b. The linear motion mechanism moves the third nozzle 43 in the horizontal and vertical directions along the guide rail.

The recovery unit 60 recovers the processing liquid supplied to the substrate W. The collection unit 60 includes, for example, a cup 61. The cup 61 surrounds the outer periphery of the substrate W held by the substrate holder 20 and receives the processing liquid splashed from the outer periphery of the substrate W. Although the cup 61 does not rotate together with the substrate holder 20 in this embodiment, it may rotate together with the substrate holder 20. A drain pipe 62 and an exhaust pipe 63 are provided at the bottom of the cup 61. The drain pipe 62 drains the liquid accumulated inside the cup 61. The exhaust pipe 63 exhausts the gas accumulated inside the cup 61.

The control unit 90 is, for example, a computer, and includes a calculation unit 91 such as a CPU (Central Processing Unit), and a storage unit 92 such as a memory. The storage unit 92 stores programs that control various processes executed in the substrate processing apparatus 1. The control unit 90 controls the operation of the substrate processing apparatus 1 by causing the calculation unit 91 to execute a program stored in the storage unit 92.

A substrate processing method according to one embodiment will be described with reference to FIGS. 3 to 6. The substrate processing method includes steps S101 to S110, for example, as shown in FIG. Steps S101 to S110 are performed under the control of the control section 90. The processing after step S101 is started when a transport device (not shown) carries the substrate W into the processing container 10. Note that the substrate processing method does not need to include all of steps S101 to S110, and may include at least steps S101, S105, and S106 in this order.

First, the substrate holding section 20 holds the substrate W horizontally, and then the substrate rotating section 25 rotates the substrate W together with the substrate holding section 20 (step S101). The substrate holder 20 holds the substrate W such that the rotation center line of the substrate W passes through the center of the front surface Wa of the substrate. In FIGS. 4 to 6, the rotation center line of the substrate W is shown by a dashed line.

While the substrate W is being rotated, steps S101 to S110 are performed on the front surface Wa of the substrate W. The surface Wa of the substrate W is the upper surface of the substrate W. Hereinafter, the surface Wa of the substrate W will also be referred to as the substrate surface Wa. Further, the position directly above the center of the substrate surface Wa is also referred to as a center position.

Next, as shown in FIG. 4(A), the first nozzle 41 supplies DHF to the substrate surface Wa (step S102). DHF is an example of a cleaning liquid. The cleaning liquid may be one containing hydrofluoric acid. The first nozzle 41 supplies DHF to the center of the substrate surface Wa at the center position. DHF flows radially outward of the substrate surface Wa due to centrifugal force, and forms a liquid film over the entire substrate surface Wa. By supplying DHF, the substrate surface Wa becomes hydrophobic.

Next, as shown in FIG. 4(B), the first nozzle 41 stops supplying DHF and supplies DIW to the substrate surface Wa (step S103). DIW is an example of pure water. The first nozzle 41 supplies DHF and DIW in this order while remaining stopped at the center position. There is no need to replace the nozzle located at the center position. DIW flows radially outward of the substrate surface Wa due to centrifugal force while displacing DHF, and forms a liquid film over the entire substrate surface Wa.

Next, the first nozzle 41 moves from the center position to the first eccentric position (the position shown in FIG. 4C) while supplying DIW to the substrate surface Wa. The first eccentric position is a position shifted outward in the radial direction of the substrate surface Wa with respect to the center position. The first eccentric position is set so that there is no hole in the center of the DIW liquid film, that is, so that the DIW liquid film covers the entire substrate surface Wa.

While the first nozzle 41 moves from the center position to the first eccentric position, the second nozzle 42 moves from the second home position to the second eccentric position (the position shown in FIG. 4(C)). The second home position is set outside the cup 61. The second eccentric position is set similarly to the first eccentric position. The second nozzle 42 does not eject DIW while moving from the second home position to the second eccentric position.

Next, as shown in FIG. 4(C), the first nozzle 41 discharges DIW at the first eccentric position, and the second nozzle 42 discharges DIW at the second eccentric position. The first nozzle 41 and the second nozzle 42 simultaneously supply DIW to the substrate surface Wa. Thereafter, the first nozzle 41 stops discharging DIW and moves to the first home position. The first home position is set outside the cup 61.

Next, the third nozzle 43 moves from the third home position to the third eccentric position (the position shown in FIG. 4(D)). The third home position is set outside the cup 61. The third eccentric position is set similarly to the first eccentric position. The third nozzle 43 does not discharge HPS while moving from the third home position to the third eccentric position.

Next, as shown in FIG. 4(D), the third nozzle 43 supplies HPS to the substrate surface Wa, and at the same time, the second nozzle 42 supplies DIW to the substrate surface Wa (step S104). HPS is an example of a hydrophilic liquid. The hydrophilic liquid may include HPS or ozone water. SC1 may be used as the hydrophilic liquid. SC1 includes HPS.

According to this embodiment, after the start of DIW supply and before the end of DIW supply, HPS supply is started. That is, according to this embodiment, DIW and HPS are supplied simultaneously. By simultaneously supplying DIW and HPS, it is possible to prevent the substrate surface Wa from drying out before the substrate surface Wa becomes sufficiently hydrophilic, and the generation of particles can be suppressed.

Next, as shown in FIG. 5(A), the third nozzle 43 moves from the third eccentric position to the center position while supplying HPS to the substrate surface Wa. Meanwhile, the second nozzle 42 moves away from the center position while supplying DIW to the substrate surface Wa so as not to hinder the movement of the third nozzle 43.

According to this embodiment, between the start of supply of DIW and the end of simultaneous supply of DIW and HPS, the nozzles located at the center position are changed from the first nozzle 41 for discharging DIW to the third nozzle for discharging HPS. Replace it with 43. While replacing the nozzle, at least one of DIW and HPS is always supplied to the substrate surface Wa. Therefore, drying of the substrate surface Wa can be suppressed, and generation of particles can be suppressed.

Note that in this embodiment, the second nozzle 42 supplies DIW to the substrate surface Wa while the nozzles are replaced, but the second nozzle 42 does not need to be used. With the first nozzle 41 and the third nozzle 43 simultaneously supplying DIW and HPS to the substrate surface Wa, the nozzle located at the center position is changed from the first nozzle 41 discharging DIW to the third nozzle 43 discharging HPS. You can also replace it with

Next, as shown in FIG. 5(B), the third nozzle 43 supplies HPS to the substrate surface Wa while remaining stopped at the center position. Meanwhile, the second nozzle 42 moves radially outward of the substrate surface Wa while supplying DIW to the substrate surface Wa. In the process of spreading the HPS liquid film concentrically, DIW can be supplied to the outside of the HPS liquid film, and drying of the substrate surface Wa can be suppressed. Note that if the substrate surface Wa is not dried, the step shown in FIG. 5(B) may be omitted.

Next, as shown in FIG. 5(C), the third nozzle 43 supplies HPS to the substrate surface Wa (step S105). The third nozzle 43 is at the center position and supplies HPS to the center of the substrate surface Wa. The HPS flows radially outward of the substrate surface Wa due to centrifugal force, and forms a liquid film over the entire substrate surface Wa. By supplying HPS, the entire substrate surface Wa can be made hydrophilic.

Next, as shown in FIG. 5(D), the third nozzle 43 stops supplying HPS and supplies SPM to the substrate surface Wa (step S106). The third nozzle 43 supplies HPS and SPM in this order while remaining stopped at the center position. There is no need to replace the nozzle located at the center position.

The SPM flows radially outward of the substrate surface Wa due to centrifugal force while displacing the HPS, and forms a liquid film over the entire substrate surface Wa. SPM removes organic matter, such as resist residue, or abrasives. The polishing agent remains on the substrate surface Wa after CMP (Chemical Mechanical Polishing).

According to this embodiment, SPM is supplied after supplying a hydrophilizing liquid such as HPS. Since SPM is supplied after the entire hydrophobic substrate surface Wa is made hydrophilic, the entire substrate surface Wa can be covered with SPM. As a result, generation of particles on the substrate surface Wa can be suppressed.

Next, as shown in FIG. 6(A), the third nozzle 43 stops supplying SPM and supplies HPS to the substrate surface Wa again (step S107). The third nozzle 43 supplies HPS, SPM, and HPS in this order while remaining stopped at the center position. There is no need to replace the nozzle located at the center position.

The HPS flows radially outward of the substrate surface Wa by centrifugal force while displacing the SPM, and forms a liquid film over the entire substrate surface Wa. By supplying HPS after supplying SPM, residual sulfur components (SO ₄ ²⁻ ) can be removed. The supply of HPS is carried out for a set time and then stopped.

Next, as shown in FIG. 6(B), the nozzle located at the center position is switched from the third nozzle 43 to the second nozzle 42, and the second nozzle 42 supplies SC1 to the substrate surface Wa (step S108). SC1 flows radially outward of the substrate surface Wa due to centrifugal force while displacing the HPS, and forms a liquid film over the entire substrate surface Wa.

SC1 is an example of an alkaline cleaning liquid. By supplying an alkaline cleaning liquid after supplying SPM, sulfur component residues and particles can be removed. The alkaline cleaning liquid suppresses the adhesion of particles by making the zeta potential of both the substrate surface Wa and the particles negative. The supply of SC1 is carried out for a set time and then stopped.

Next, as shown in FIG. 6(C), the nozzle located at the center position is switched from the second nozzle 42 to the fourth nozzle 44, and the fourth nozzle 44 supplies a mixed fluid of DIW and gas to the substrate surface Wa. (Step S109). Fine droplets of DIW collide with the substrate surface Wa, and the impact removes particles. The fourth nozzle 44 may move in the radial direction of the substrate surface Wa while supplying the mixed fluid of DIW and gas to the substrate surface Wa.

Next, as shown in FIG. 6(D), after all the processing liquids have been supplied, the substrate rotating section 25 rotates the substrate W together with the substrate holding section 20, thereby spin drying the substrate W (step S110). The method of drying the substrate W is not limited to spin drying, and may be, for example, supercritical drying. Supercritical drying is performed inside a pressure vessel separate from the processing vessel 10.

Although the embodiments of the substrate processing method and substrate processing apparatus according to the present disclosure have been described above, the present disclosure is not limited to the above embodiments. Various changes, modifications, substitutions, additions, deletions, and combinations are possible within the scope of the claims. These naturally fall within the technical scope of the present disclosure.

This application claims priority based on Japanese Patent Application No. 2022-111930 filed with the Japan Patent Office on July 12, 2022, and the entire content of Japanese Patent Application No. 2022-111930 is incorporated into this application. .

1 Substrate processing apparatus 20 Substrate holding section 25 Substrate rotation section 31 First supply section 32 Second supply section 33 Third supply section 90 Control section W Substrate Wa Substrate surface

Claims

Holding the board horizontally and rotating it;
Supplying a hydrophilic solution containing hydrogen peroxide or ozone water to the hydrophobic surface of the rotating substrate;
After supplying the hydrophilizing liquid, supplying a mixed solution of sulfuric acid and hydrogen peroxide to the surface of the rotating substrate;
A substrate processing method comprising:
2. The substrate processing method according to claim 1, further comprising supplying a cleaning solution containing hydrofluoric acid to the surface of the rotating substrate before supplying the hydrophilizing solution.
3. The substrate processing method according to claim 2, further comprising supplying, after supplying the cleaning liquid, pure water to replace the cleaning liquid to the surface of the rotating substrate.
After the start of the supply of the pure water and before the end of the supply of the pure water, the supply of the hydrophilic liquid is started,
4. The substrate processing method according to claim 3, further comprising simultaneously supplying the pure water and the hydrophilizing liquid to the surface of the rotating substrate.
Between the start of the supply of the pure water and the end of the simultaneous supply of the pure water and the hydrophilizing liquid, a nozzle located directly above the center of the surface of the substrate is moved from a nozzle that discharges the pure water, 5. The substrate processing method according to claim 4, further comprising replacing the nozzle with a nozzle that discharges the hydrophilic liquid.
While simultaneously supplying the pure water and the hydrophilizing liquid to the surface of the rotating substrate, the nozzle for discharging the hydrophilic liquid is stopped right above the center of the surface of the substrate, and the 6. The substrate processing method according to claim 4, further comprising moving a nozzle that discharges pure water radially outward of the substrate.
The substrate processing according to any one of claims 1 to 5, comprising supplying the hydrophilizing liquid and the mixed liquid in this order from the same nozzle to the surface of the rotating substrate. Method.
6. The method according to claim 1, further comprising supplying a hydrogen peroxide solution to the surface of the rotating substrate while stopping the supply of sulfuric acid after supplying the mixed liquid. substrate processing method.
9. The substrate processing method according to claim 8, comprising supplying an alkaline cleaning liquid to the surface of the rotating substrate after supplying hydrogen peroxide solution with the supply of sulfuric acid being stopped.
After supplying the alkaline cleaning liquid, supplying a mixed fluid of pure water and gas to the surface of the rotating substrate;
Drying the substrate by rotating the substrate after supplying the mixed fluid of the pure water and the gas;
The substrate processing method according to claim 9, comprising:
a board holder that holds the board horizontally;
a substrate rotating section that rotates the substrate holding section;
a supply unit that supplies a processing liquid to the surface of the substrate held by the substrate holding unit;
a control unit that controls the substrate rotation unit and the supply unit;
Equipped with
The control unit includes:
Supplying a hydrophilic solution containing hydrogen peroxide or ozone water to the hydrophobic surface of the rotating substrate;
After supplying the hydrophilizing liquid, supplying a mixed solution of sulfuric acid and hydrogen peroxide to the surface of the rotating substrate;
Substrate processing equipment that performs