KR102497589B1 - Substrate processing method and substrate processing apparatus - Google Patents

Abstract

A substrate processing method is a method of treating a substrate by supplying a chemical solution to a surface of a substrate on which a pattern is formed, comprising: a substrate holding step for holding a substrate; a chemical solution supplying step for supplying the chemical solution to at least the surface of a substrate; Prior to the supplying step, a low-conductivity liquid supply step of supplying a low-conductivity liquid having a conductivity lower than that of the chemical liquid to the surface of the substrate to neutralize static electricity on the substrate; To do this, a high conductivity liquid supplying step of supplying a high conductivity liquid having a conductivity lower than that of the chemical liquid and higher than that of the low conductivity liquid to the back surface of the substrate, which is opposite to the front surface, instead of the front surface of the substrate.

Description

Substrate processing method and substrate processing apparatus

The present invention relates to a substrate processing method and a substrate processing apparatus for treating the surface of a substrate. Substrates to be treated include, for example, semiconductor wafers, liquid crystal display substrates, FPD (Flat Panel Display) substrates such as organic EL (electroluminescence) display devices, optical disk substrates, magnetic disk substrates, and optical disk substrates. A substrate for a magnetic disk, a substrate for a photomask, a ceramic substrate, a substrate for a solar cell, and the like are included.

In a semiconductor device manufacturing process, for example, a single-wafer type substrate processing apparatus for processing substrates one by one includes a processing chamber, a spin chuck for rotating the substrate while holding the substrate substantially horizontally in the processing chamber; A nozzle is provided for discharging the chemical liquid toward the surface of the substrate rotated by the spin chuck (a surface on which a pattern (device) is formed).

In substrate processing using such a substrate processing apparatus, a liquid chemical is discharged from a nozzle toward, for example, the central portion of the surface of a substrate in a rotating state, for example. The chemical solution supplied to the central portion of the surface of the substrate receives the centrifugal force generated by the rotation of the substrate, flows on the surface of the substrate toward the circumferential edge, and spreads evenly over the entire surface of the substrate. In this way, the entire surface of the substrate is treated with the chemical solution.

In the substrate carried into the processing chamber, charges may be accumulated (that is, charged) on the surface of the substrate due to previous steps (ion implantation and dry etching). If charges are accumulated on the surface of the substrate carried into the processing chamber, when the chemical liquid from the nozzle contacts the surface of the substrate, the chemical liquid contacts the surface of the substrate, resulting in a rapid change in charge on the surface of the substrate. As a result, there is a risk of electrostatic discharge (arking) occurring at or near the liquid contact position. As a result, local defects may occur on the surface of the substrate, such as destruction of the pattern (device) or hole in the pattern.

Therefore, in Patent Document 1 below, in order to prevent the occurrence of electrostatic discharge on the surface of the substrate at the time of starting the supply of the chemical solution, before starting the supply of the chemical solution, a neutralizing liquid having a lower conductivity than that of the chemical solution (for example, For example, carbonated water) is known to be supplied to the surface of a substrate.

Specification of US Patent Application Publication No. 2009/211610

However, there are cases in which the amount of charge on the substrate carried into the processing chamber is large. Since charge transfer is fast in the static elimination using carbonated water, when the carbonated water comes into contact with the substrate, an electrostatic discharge may occur as the carbonated water contacts the surface of the substrate.

In addition, in order to gradually decrease the amount of charge on the substrate, it is also possible to supply an elimination liquid (for example, DIW (deionized water)) having a lower conductivity than carbonated water to the surface of the substrate, and then supply carbonated water to the surface of the substrate. can think However, when the amount of charge on the substrate is large, electrostatic discharge may occur even when DIW is supplied to the surface of the substrate.

That is, it is necessary to suppress or prevent the occurrence of electrostatic discharge accompanying the supply of the chemical solution to the substrate, and to suppress or prevent the occurrence of electrostatic discharge accompanying the supply of the antiseptic liquid (carbonated water or DIW) to the substrate. . In other words, it is necessary to suppress or prevent the occurrence of electrostatic discharge accompanying the supply of liquid to the substrate.

Therefore, an object of the present invention is to be able to suppress or prevent the occurrence of electrostatic discharge accompanying the supply of liquid to the surface of the substrate, thereby suppressing or preventing the occurrence of local defects on the surface of the substrate. It is to provide a substrate processing method and a substrate processing apparatus.

The present invention is a method of treating a substrate by supplying a chemical solution to the surface of a substrate on which a pattern is formed, comprising: a substrate holding step for holding a substrate; a chemical solution supplying step for supplying the chemical solution to at least the surface of a substrate; Prior to the process, a low-conductivity liquid supply step of supplying a low-conductivity liquid having a conductivity lower than that of the chemical liquid to the surface of the substrate to neutralize the substrate, and prior to the low-conductivity liquid supply step, to neutralize the substrate and a high conductivity liquid supplying step of supplying a high conductivity liquid having a conductivity lower than that of the chemical liquid and higher than that of the low conductivity liquid to a back surface of the substrate, which is opposite to the surface, instead of to the surface of the substrate. processing method is provided.

According to this method, prior to supplying the chemical solution to the substrate, first, the highly conductive liquid is supplied to the back surface of the substrate instead of the front surface of the substrate. When the substrate is charged, since charges are accumulated on the surface of the substrate (device surface on which devices are formed), even if a highly conductive liquid is supplied to the back surface of the substrate, electrostatic discharge rarely occurs on the back surface of the substrate. In addition, since the conductivity of the highly conductive liquid is relatively high, the amount of charge stored in the substrate can be effectively reduced by supplying the low conductive liquid to the back surface of the substrate.

In addition, by supplying the highly conductive liquid to the back surface of the substrate, the charge that has entered the inside of the pattern on the surface of the substrate can be taken out to the outer surface of the pattern.

Then, a low-conductivity liquid is supplied to the surface of the substrate. In this way, the charge that has escaped to the outer surface of the pattern can be effectively removed by the low-conductivity liquid. Since the conductive liquid is supplied to the surface of the substrate after the amount of charge from the substrate is reduced, occurrence of electrostatic discharge can be effectively suppressed or prevented. In addition, since the conductive liquid is a low-conductivity liquid having a relatively low conductivity, generation of electrostatic discharge can be suppressed or prevented more effectively.

Then, the chemical solution is supplied to at least the surface of the substrate after the electric charges have been sufficiently removed by the low-conductivity liquid and the high-conductivity liquid. In this way, chemical liquid treatment is executed. Therefore, generation of electrostatic discharge accompanying the supply of the chemical solution to the surface of the substrate can be suppressed or prevented.

This makes it possible to suppress or prevent the occurrence of electrostatic discharge accompanying the supply of liquid (low-conductivity liquid, high-conductivity liquid, chemical liquid) to the surface of the substrate, thereby preventing the occurrence of local defects on the surface of the substrate. can be suppressed or prevented.

In one embodiment of the present invention, the substrate processing method includes a step of supplying the low-conductivity liquid or the high-conductivity liquid to the back surface of the substrate in parallel with the low-conductivity liquid supply step to neutralize the substrate. include additional

According to this method, the low-conductivity liquid or high-conductivity liquid is supplied to the back surface of the substrate in parallel with the supply of the low-conductivity liquid to the front surface of the substrate. This makes it possible to more effectively remove the charges accumulated on the substrate. Therefore, it is possible to more effectively suppress or prevent the occurrence of electrostatic discharge at the time of supplying the chemical solution.

In another embodiment of the present invention, in parallel to the highly conductive liquid supplying step, no liquid is supplied to the surface of the substrate.

If the liquid is supplied to the surface of the substrate in parallel with the supply of the highly conductive liquid to the back surface of the substrate, electrostatic discharge may occur on the surface of the substrate due to the liquid adhering to the surface of the substrate.

In contrast, according to this method, the liquid is not supplied to the surface of the substrate in parallel with the supply of the highly conductive liquid to the back surface of the substrate. Thereby, generation of electrostatic discharge on the surface of the substrate can be more effectively suppressed or prevented.

In one embodiment of the present invention, in the substrate processing method, in parallel with the highly conductive liquid supplying step, an opposing member having a substrate facing surface facing the entire surface of the substrate is provided, so that the substrate facing surface is above the surface of the substrate. It further includes a proximal position placement process for disposing in a proximal position proximate to the surface.

According to this method, the highly conductive liquid is supplied to the back surface of the substrate while bringing the substrate facing surface of the opposing member close to the substrate surface, that is, while protecting the substrate surface with the substrate facing surface of the opposing member. Therefore, it is possible to satisfactorily suppress or prevent the flow of the highly conductive liquid from the back side of the substrate to the front surface side of the substrate and the flow of the highly conductive liquid to the front surface side of the substrate.

In another embodiment of the present invention, the substrate processing method includes supplying the highly conductive liquid to at least the surface of the substrate in order to neutralize the substrate after the low-conductive liquid supplying step and before the chemical solution supplying step. A second highly conductive liquid supply process is further included.

According to this method, after the low-conductivity liquid is supplied to the substrate, the high-conductivity liquid is supplied to at least the surface of the substrate during the period until the chemical liquid is supplied to the substrate. In short, the low-conductivity liquid → high-conductivity liquid is supplied to the surface of the substrate in the order. Since low-conductive liquid → high-conductive liquid → chemical liquid and conductive liquid are supplied step by step in order from the low-conductive liquid, the occurrence of electrostatic discharge caused by the low-conductive liquid or the high-conductive liquid is prevented, and the board is discharged satisfactorily. In addition, the occurrence of electrostatic discharge during supply of the chemical solution can be effectively suppressed.

In one embodiment of this invention, the substrate holding step includes a step of holding the substrate by bringing a conductive portion formed using a conductive material into contact with a peripheral portion of the substrate.

According to this method, the substrate can be satisfactorily discharged through the low-conductivity liquid or the high-conductivity liquid.

Further, the low-conductivity liquid may contain deionized water. The highly conductive liquid may contain a liquid containing ions.

The present invention provides a substrate holding unit for holding a substrate having a pattern formed thereon, a chemical solution supplying unit for supplying a chemical solution having conductivity to the surface of the substrate held by the substrate holding unit, and the substrate holding unit. a low-conductivity liquid supply unit for supplying a low-conductivity liquid having a conductivity lower than that of the chemical liquid to the surface of the substrate held by the substrate holding unit; On the back side, a high conductivity liquid supply unit for supplying a high conductivity liquid having a conductivity lower than that of the chemical liquid and higher than that of the low conductivity liquid, and the chemical liquid supply unit, the low conductivity liquid supply unit, and the high conductivity liquid supply unit. a chemical solution supplying step of supplying the chemical solution to at least the surface of the substrate, and prior to the chemical solution supplying step, to remove static electricity from the substrate, to the surface of the substrate; A low-conductivity liquid supplying step of supplying a conductive liquid, and prior to the low-conductivity liquid supplying step, the high-conductivity liquid is supplied not to the front surface of the substrate, but to the back surface of the substrate opposite to the front surface. A substrate processing apparatus that performs a supply process is provided.

According to this configuration, prior to supplying the chemical liquid to the substrate, first, the highly conductive liquid is supplied to the back surface of the substrate instead of the front surface of the substrate. When the substrate is charged, since charges are accumulated on the surface of the substrate (device surface on which devices are formed), even if a highly conductive liquid is supplied to the back surface of the substrate, electrostatic discharge rarely occurs on the back surface of the substrate. In addition, since the conductivity of the highly conductive liquid is relatively high, the amount of charge stored in the substrate can be effectively reduced by supplying the low conductive liquid to the back surface of the substrate.

In addition, by supplying the highly conductive liquid to the back surface of the substrate, the charge that has entered the inside of the pattern on the surface of the substrate can be taken out to the outer surface of the pattern.

Then, a low-conductivity liquid is supplied to the surface of the substrate. In this way, the charge that has escaped to the outer surface of the pattern can be effectively removed by the low-conductivity liquid. Since the conductive liquid is supplied to the surface of the substrate after the amount of charge from the substrate is reduced, occurrence of electrostatic discharge can be effectively suppressed or prevented. In addition, since the conductive liquid is a low-conductivity liquid having a relatively low conductivity, generation of electrostatic discharge can be suppressed or prevented more effectively.

Then, the chemical solution is supplied to at least the surface of the substrate after the electric charges have been sufficiently removed by the low-conductivity liquid and the high-conductivity liquid. In this way, chemical liquid treatment is executed. Therefore, generation of electrostatic discharge accompanying the supply of the chemical solution to the surface of the substrate can be suppressed or prevented.

This makes it possible to suppress or prevent the occurrence of electrostatic discharge accompanying the supply of liquid (low-conductivity liquid, high-conductivity liquid, chemical liquid) to the surface of the substrate, thereby preventing the occurrence of local defects on the surface of the substrate. can be suppressed or prevented.

In one embodiment of the present invention, the substrate processing apparatus has a substrate facing surface facing the entire surface of the substrate held by the substrate holding unit, and the substrate facing surface is close to the surface of the substrate. It further includes an opposing member disposed in a proximate position.

According to this configuration, it is possible to supply the highly conductive liquid to the back surface of the substrate while bringing the substrate facing surface of the opposing member close to the substrate surface, that is, while protecting the substrate surface with the substrate facing surface of the opposing member. In this case, it is possible to satisfactorily suppress or prevent the flow of the highly conductive liquid from the back surface of the substrate to the surface side of the substrate and the flow of the highly conductive liquid to the surface side of the substrate.

In one embodiment of this invention, the substrate holding unit has a conductive pin formed using a conductive material as a holding pin for contacting and supporting the circumferential edge portion of the substrate.

According to this configuration, the substrate can be satisfactorily discharged through the low-conductivity liquid or the high-conductivity liquid.

The above-mentioned and other objects, characteristics, and effects in the present invention will become clear from the description of the following embodiments with reference to the accompanying drawings.

1 is a schematic plan view for explaining the internal layout of a substrate processing apparatus according to an embodiment of the present invention.
2 is a schematic cross-sectional view for explaining a configuration example of a processing unit included in the substrate processing apparatus.
3 is a block diagram for explaining the electrical configuration of main parts of the substrate processing apparatus and a cross-sectional view showing an enlarged surface of a substrate to be processed by the substrate processing apparatus.
4 is a flowchart for explaining a first substrate processing example by the processing unit.
5A to 5C are schematic views of the substrate viewed horizontally when each step of the first substrate processing example is being executed.
6A to 6C are diagrams for explaining changes in the electrification state of the substrate in each step of the first substrate processing example.
7A to 7C are diagrams for explaining contents of a chemical solution supplying step included in a first substrate processing example.
8 is a diagram showing the test results of the static elimination test.
9 is a flowchart for explaining a second substrate processing example executed by the processing unit.
10 is a flowchart for explaining a third substrate processing example executed by the processing unit.

1 is a schematic diagram of a substrate processing apparatus 1 according to an embodiment of the present invention viewed from above. The substrate processing apparatus 1 is a single wafer type apparatus that processes substrates W such as silicon wafers one by one. In this embodiment, the substrate W is a disk-shaped substrate. The substrate processing apparatus 1 includes a plurality of processing units 2 for processing substrates W with a processing liquid and a rinsing liquid, and a substrate container for accommodating a plurality of substrates W processed by the processing units 2. A load port (LP) on which is placed, an indexer robot (IR) and a substrate transfer robot (CR) that transport the substrate W between the load port (LP) and the processing unit 2, and substrate processing and a control device (3) that controls the device (1). The indexer robot IR transports the substrate W between the substrate container and the substrate transfer robot CR. The substrate transfer robot CR transfers the substrate W between the indexer robot IR and the processing unit 2 . A plurality of processing units 2 have the same configuration, for example.

2 is a schematic cross-sectional view for explaining a configuration example of the processing unit 2. As shown in FIG.

The processing unit 2 maintains a box-shaped processing chamber 4 and a substrate W in a horizontal position in the processing chamber 4, and rotates a vertical axis of rotation passing through the center of the substrate W. (A1) a spin chuck (substrate holding unit) 5 for rotating the substrate W around, and an upper surface of the substrate W held by the spin chuck 5 (surface of the substrate W (pattern formation surface) ) (Wa) (see FIG. 5A and the like)) an upper liquid supply unit for supplying liquid (treatment liquid (chemical liquid and rinsing liquid) and removal liquid) to the substrate W held by the spin chuck 5 a lower liquid supply unit for supplying liquid (treatment liquid (chemical liquid and rinsing liquid) and removal liquid) to the lower surface (rear surface Wb of the substrate W (see FIG. 5A and the like)), and a spin chuck 5 Ordinary processing of surrounding the opposite member 6 facing the upper surface of the substrate W held thereon and shielding the space above the substrate W from the surrounding atmosphere, and the side of the spin chuck 5 A cup (not shown) is included.

The processing chamber 4 includes a box-shaped partition wall 7 accommodating the spin chuck 5 and the like.

As the spin chuck 5, a clamp-type chuck that holds the substrate W horizontally with the substrate W interposed therebetween in the horizontal direction is employed. Specifically, the spin chuck 5 includes a spin motor (rotation unit) 12, a haspin shaft 13 integrated with the drive shaft of the spin motor 12, and an upper end of the haspin shaft 13 ( and a disk-shaped spin base 14 mounted substantially horizontally on the upper section). The heart pin shaft 13 is formed using a conductive material. The heart pin shaft 13 is ground-connected.

The spin base 14 includes a horizontal circular upper surface 14a having an outer diameter larger than that of the substrate W. The spin base 14 is formed using a conductive material. On the upper surface 14a, a plurality of (three or more, for example, six) clamping pins 15 are disposed on the periphery thereof. The plurality of clamping pins 15 are arranged at appropriate intervals, for example, at equal intervals on the circumference corresponding to the outer circumferential shape of the substrate W at the circumferential portion of the upper surface of the spin base 14 . The holding pin 15 is a so-called conductive pin formed using a conductive material.

As described above, the heart pin shaft 13, the spin base 14, and the holding pin 15 are each formed using a conductive material (for example, a conductive material containing carbon or a metal material), Also, the heart pin shaft 13 is connected to earth. Therefore, when a liquid having conductivity (a low-conductivity liquid, a high-conductivity liquid, and a chemical liquid to be described later) is supplied to the front or rear surface of the substrate W held by the spin chuck 5, the substrate (W ) is discharged.

The opposing member 6 includes an opposing plate 17 and an upper surface nozzle 30 penetrating the central portion of the opposing plate 17 in the vertical direction. The opposing plate 17 has on its lower surface a horizontally arranged circular substrate opposing surface 17a that opposes the entire upper surface of the substrate W.

In this embodiment, the upper surface nozzle 30 functions as a central axis nozzle. The upper surface nozzle 30 is disposed above the spin chuck 5 . The upper surface nozzle 30 is supported by a support arm 22 . The upper surface nozzle 30 is non-rotatable relative to the support arm 22 . The upper surface nozzle 30 moves up and down together with the opposing plate 17 and the support arm 22 . The upper surface nozzle 30 has a discharge port 30a at its lower end, which faces the central part of the upper surface of the substrate W held by the spin chuck 5 .

An opposing member elevating unit 27 having a configuration including an electric motor, a ball screw, and the like is coupled to the support arm 22 . The opposing member elevating unit 27 vertically moves the opposing member 6 (the opposing plate 17 and the upper spin shaft 18 ) and the upper surface nozzle 30 together with the support arm 22 .

The opposing member elevating unit 27 moves the opposing plate 17 to a position where the substrate opposing surface 17a is close to the upper surface of the substrate W held by the spin chuck 5 (2-dot chain line in FIG. 2). It is moved up and down between a position indicated by (see also Fig. 5A) and a retracted position (a position indicated by a solid line in Fig. 2) retracted upward to a greater extent than the proximate position. The opposing member elevating unit 27 can hold the opposing plate 17 at the proximity position (position shown in Fig. 5A), the upper position (position shown in Figs. 5B and 5C), and the retracted position. The proximity position is a position where the substrate facing surface 17a is disposed with a small gap (for example, about 0.3 mm) between it and the upper surface of the substrate W. The difference value is a position where the distance between the substrate facing surface 17a and the upper surface of the substrate W is larger than the proximity position and smaller than the retracted position.

The upper liquid supply unit includes an upper nozzle 30, a first upper supply unit 31, a second upper supply unit 32, and a third upper supply unit 33 respectively supplying treatment liquid to the upper nozzle 30. ), including

The first upper supply unit 31 includes an upper common pipe 35 having one end connected to the upper surface nozzle 30 and an upper common pipe 35 connected to the other end of the upper common pipe 35 . The upper mixing valve unit (UMV) includes an upper connection portion 36 for supplying liquid to the upper common pipe 35 and a plurality of valves. Inside the upper connection portion 36, a circulation space for the flow of liquid is formed. The upper mixing valve unit (UMV) further includes a DIW upper pipe 37, an SC2 upper pipe 38 and an upper suction pipe 39 connected to the upper connection portion 36, respectively. A plurality of valves included in the upper mixing valve unit (UMV) include a DIW upper valve 42 that opens and closes the DIW upper pipe 37, an SC2 upper valve 43 that opens and closes the SC2 upper pipe 38, An upper suction valve 44 for opening and closing the suction pipe 39 is included.

DIW (deionized water) from a DIW supply source is supplied to the DIW upper pipe 37. When the DIW upper valve is opened in a state where the other valves included in the upper liquid supply unit are closed, DIW is supplied to the upper nozzle 30, whereby the DIW is discharged downward from the discharge port 30a.

SC2 (a mixed liquid containing HCl and H ₂ O ₂ ) is supplied from the SC2 supply source to the SC2 upper pipe 38 . When the SC2 upper valve 43 is opened while the other valves included in the upper liquid supply unit are closed, SC2 is supplied to the upper nozzle 30, whereby SC2 is discharged downward from the discharge port 30a.

A suction device (not shown) is connected to the downstream end of the upper suction pipe 39 . The suction device is, for example, an ejector type suction device. An ejector-type suction device includes a vacuum generator and an aspirator. In the operating state of the suction device, when the inside of the suction device is depressurized, the inside of the upper suction pipe 39 is sucked, and as a result, the function of the suction device is effective. In the state in which the function of the suction device is enabled, the upper suction valve 44 is opened while the other valves included in the upper liquid supply unit are closed, so that the inside of the upper suction pipe 39 is sucked, and the upper connection portion ( The liquid in the inner space (circulation space) of 36) and the liquid inside the upper common pipe 35 are sucked by the suction device.

The second upper supply unit 32 includes an SC1 upper pipe 46 connected to the upper surface nozzle 30 and an SC1 upper valve 47 interposed in the SC1 upper pipe 46. SC1 (a mixed liquid containing NH ₄ OH and H ₂ O ₂ ) is supplied from the SC1 supply source to the SC1 upper pipe 46 . When the SC1 upper valve 47 is opened while the other valves included in the upper liquid supply unit are closed, SC1 is supplied to the upper surface nozzle 30, whereby SC1 is discharged downward from the discharge port 30a.

The third phase supply unit 33 includes an HF phase pipe 48 connected to the upper surface nozzle 30 and an HF phase valve 49 interposed in the HF phase pipe 48 . HF from the HF supply source is supplied to the HF phase pipe 48. When the HF upper valve 49 is opened while the other valves included in the upper liquid supply unit are closed, HF is supplied to the upper nozzle 30, whereby HF is discharged downward from the discharge port 30a. In this embodiment, HF is, for example, diluted dilute hydrofluoric acid (DHF).

In this embodiment, the low-conductivity liquid supply unit is constituted by the upper surface nozzle 30, the DIW upper pipe 37, and the DIW upper valve 42.

The lower liquid supply unit includes a first lower supply unit 51, a second lower supply unit 52, and a third lower supply unit 53 respectively supplying treatment liquid to the lower surface nozzle 50 and the lower surface nozzle 50. ), including

The first lower supply unit 51 includes a lower common pipe 55 having one end connected to the lower surface nozzle 50 and a lower mixing valve unit (DMV) connected to the other end of the lower common pipe 55. The lower mixing valve unit (DMV) includes a lower connection portion 56 for feeding liquid to the lower common pipe 55 and a plurality of valves. Inside the lower connection portion 56, a circulation space for the flow of liquid is formed. The lower mixing valve unit (DMV) adds a DIW lower pipe (57), an SC2 lower pipe (58), a CO ₂ water lower pipe (60) and a lower suction pipe (59) connected to the lower connection part (56), respectively. to include A plurality of valves included in the lower liquid supply unit include a DIW lower valve 62 that opens and closes the DIW lower pipe 57, an SC2 lower valve 63 that opens and closes the SC2 lower pipe 58, and a CO ₂ lower valve. It includes a CO ₂ draining valve 65 that opens and closes the pipe 60 and a low suction valve 64 that opens and closes the low suction pipe 59 .

DIW from the DIW supply source is supplied to the DIW lower pipe 57. When the DIW lower valve 62 is opened in a state in which the other valves included in the lower mixing valve unit (DMV) are closed, DIW is supplied to the lower surface nozzle 50, whereby the DIW is discharged upward from the discharge port 50a. do.

SC2 from the SC2 supply source is supplied to the SC2 lower pipe 58. When the SC2 lower valve 63 is opened in a state where the other valves included in the lower liquid supply unit are closed, SC2 is supplied to the lower surface nozzle 50, whereby SC2 is discharged upward from the discharge port 50a.

CO ₂ water from a CO ₂ water supply source is supplied to the CO ₂ water lower pipe 60 . The CO ₂ water lower valve 65 is opened in a state in which the other valves included in the lower liquid supply unit are closed, so that the CO ₂ water is supplied to the lower surface nozzle 50, thereby increasing the CO ₂ water from the discharge port 50a upward. is discharged

A suction device (not shown) is connected to the downstream end of the lower suction pipe 59 . The suction device is, for example, an ejector type suction device. An ejector-type suction device includes a vacuum generator and an aspirator. In the operating state of the suction device, when the inside of the suction device is depressurized, the inside of the lower suction pipe 59 is sucked, and as a result, the function of the suction device is effective. In the state in which the function of the suction device is enabled, the lower suction valve 64 is opened while the other valves included in the lower liquid supply unit are closed, so that the inside of the lower suction pipe 59 is sucked, and the lower connection portion ( The liquid in the internal space (distribution space) of 56 and the liquid inside the lower bore pipe 55 are sucked by the suction device.

The second lower supply unit 52 includes an SC1 lower pipe 66 connected to the lower surface nozzle 50. It includes an SC1 lower valve (67) individually mounted on the SC1 lower pipe (66). SC1 from the SC1 supply source is supplied to the SC1 lower pipe 66. When the SC1 lower valve 67 is opened in a state where the other valves included in the lower liquid supply unit are closed, SC1 is supplied to the lower surface nozzle 50, whereby SC1 is discharged upward from the discharge port 50a.

The third lower supply unit 53 includes an HF lower pipe 68 connected to the lower surface nozzle 50 and HF lower valves 69 individually attached to the HF lower pipe 68. HF from the HF supply source is supplied to the HF lower pipe 68. When the HF lower valve 69 is opened while the other valves included in the lower liquid supply unit are closed, HF is supplied to the lower nozzle 50, whereby HF is discharged upward from the discharge port 50a. In this embodiment, HF is, for example, diluted dilute hydrofluoric acid (DHF).

In this embodiment, the highly conductive liquid supply unit is constituted by the lower surface nozzle 50, the CO ₂ drain pipe 60, and the CO ₂ drain valve 65.

3A is a block diagram for explaining the electrical configuration of main parts of the substrate processing apparatus 1 .

The control device 3 is configured using, for example, a microcomputer. The control device 3 has an arithmetic unit such as a CPU, a storage unit such as a fixed memory device and a hard disk drive, and an input/output unit. A program to be executed by the arithmetic unit is stored in the storage unit.

In addition, the spin motor 12, the opposing member elevating unit 27, and the like are connected to the control device 3 as control objects. The control device 3 controls the operations of the spin motor 12, the opposing member elevating unit 27 and the like according to a predetermined program.

In addition, the control device 3, according to a predetermined program, the DIW upper valve 42, the SC2 upper valve 43, the upper suction valve 44, the SC1 upper valve 47, the HF upper valve 49, Open and close the DIW lower valve 62, the SC2 lower valve 63, the lower suction valve 64, the CO ₂ lower valve 65, the SC1 lower valve 67, and the HF lower valve 69.

Hereinafter, the case of processing the substrate W on which the pattern 100 is formed on the surface (surface) Wa, which is the pattern formation surface (device formation surface), will be described.

FIG. 3B is a cross-sectional view showing the surface Wa of the substrate W, which is an object of processing by the substrate processing apparatus 1, on an enlarged scale. The substrate W to be processed is, for example, a silicon wafer, and the pattern 100 is formed on the surface Wa, which is the pattern formation surface. The pattern 100 is, for example, a fine pattern. As shown in FIG. 3B , the pattern 100 may be one in which structures 101 having a convex shape (columnar shape) are arranged in a matrix form. In this case, the line width W1 of the structure 101 is, for example, about 3 nm to 45 nm, and the gap W2 of the pattern 100 is, for example, about 10 nm to several micrometers. The film thickness T of the pattern 100 is about 0.2 μm to 1.0 μm, for example. In addition, the pattern 100 may have, for example, an aspect ratio (ratio of the film thickness T to the line width W1) of, for example, about 5 to 500 (typically, about 5 to 50 am).

In addition, the pattern 100 may be a line-shaped pattern formed by fine trenches repeatedly arranged in a row. Alternatively, the pattern 100 may be formed by forming a plurality of micropores (voids or pores) in a thin film.

The pattern 100 includes, for example, an insulating film. In addition, the pattern 100 may contain a conductor film. More specifically, the pattern 100 is formed of a laminated film in which a plurality of films are laminated, and may further include an insulating film and a conductor film. The pattern 100 may be a pattern composed of a single layer film. The insulating film may be a silicon oxide film (SiO ₂ film) or a silicon nitride film (SiN film). Further, the conductor film may be an amorphous silicon film into which impurities are introduced for low resistance, or may be a metal film (for example, a TiN film).

In addition, the pattern 100 may be a hydrophilic film. As the hydrophilic film, a TEOS film (a type of silicon oxide film) can be exemplified.

4 is a flowchart for explaining the contents of the first substrate processing example executed in the processing unit 2 . 5A to 5C are schematic views of the substrate viewed horizontally when each step of the first substrate processing example is being executed. 6A to 6C are diagrams for explaining changes in the electrification state of the substrate W in each step of the first substrate processing example.

Referring to Figs. 1 to 4, a first substrate processing example will be described. 5A to 6C will be appropriately described. A first substrate treatment example is a cleaning treatment for removing foreign matter (particles) from the surface of the substrate W. Similar to the second substrate processing example and the third substrate processing example described later, cleaning processing is performed to remove foreign substances from the surface of the substrate W.

An unprocessed substrate W (for example, a circular substrate having a diameter of 300 mm) is carried from the substrate container C to the processing unit 2 by the indexer robot IR and the substrate transfer robot CR, and is carried into the processing chamber 4, the substrate W is delivered to the spin chuck 5 with its surface Wa (pattern formation surface, device formation surface, see Fig. 3B, etc.) facing upward, and the spin chuck 5 ), the substrate W is held (substrate holding step. S1 in FIG. 4: carrying in the substrate W). In this state, the back surface Wb of the substrate W (see FIG. 6A and the like) faces downward.

In the substrate carried into the inner space of the processing chamber 4, charges may be accumulated (ie, charged) on the substrate W due to the preceding process (ion implantation, dry etching). When the substrate W is charged, the charge is mainly accumulated on the surface Wa of the substrate W, as shown in FIG. 6A . More specifically, the charge enters the inside of the pattern 100 on the surface Wa of the substrate W. When a chemical solution (conductive chemical solution such as SC1 or SC2) is supplied to the substrate W, the surface Wa of the substrate W comes into contact with the chemical solution, resulting in a rapid electric charge on the surface Wa of the substrate W. A change may occur and electrostatic discharge may occur at or near the liquid contact position of the chemical liquid. As a result, local defects may occur on the surface Wa of the substrate W, for example, the pattern 100 is destroyed or a hole is formed in the pattern 100 . Therefore, prior to the chemical solution supplying step S5, in order to neutralize the substrate W, the high-conductivity liquid supplying step S3 and the low-conductive liquid supplying step S4 are executed.

After the substrate transfer robot CR is retracted out of the processing unit 2, the controller 3 controls the spin motor 12 to set the rotation speed of the spin base 14 to a predetermined static elimination rotation speed (about 500 rpm, for example, up to about 200 rpm), and maintained at that static elimination rotation speed (S2 in FIG. 4: substrate W rotation start).

Further, the control device 3 controls the opposing member elevating unit 27 to lower the opposing plate 17 from the retracted position and dispose it to the proximal position as shown in FIG. 5A.

When the rotation of the substrate W reaches the static elimination rotation speed, the control device 3 generates CO as a highly conductive liquid (a liquid having lower conductivity than the chemical liquids (eg, SC1 and SC2)), as shown in FIG. 5A . A highly conductive liquid supplying step (S3 in FIG. 4) of supplying ₂ water to the back surface Wb of the substrate W instead of the front surface Wa of the substrate W is executed. Since CO ₂ water contains ions, it has a somewhat high electrical conductivity. The electrical resistivity of the CO ₂ water supplied to the substrate W in the highly conductive liquid supply step S3 (the lower the electrical resistivity, the higher the electrical conductivity) is, for example, in the range of 10 ⁻⁶ MΩ·cm to 20 MΩ·cm And, more specifically, from about 20 MΩ cm to about 30 MΩ cm.

Specifically, the control device 3 opens the CO ₂ draining valve 65 . As a result, CO ₂ water is discharged from the discharge port 50a of the lower surface nozzle 50 toward the central portion of the lower surface Wb (ie, lower surface) of the substrate W in a rotating state. The CO ₂ water adhering to the back surface Wb of the substrate W receives the centrifugal force caused by the rotation of the substrate W and moves to the periphery of the substrate W. Thus, a liquid film of CO ₂ water covering the entire surface of the back surface Wb of the substrate W is formed.

Since the conductivity of the CO ₂ water is relatively high, supply of the CO ₂ water as a highly conductive liquid to the back surface Wb of the substrate W reduces the amount of charge accumulated in the pattern 100 of the substrate W. can be effectively reduced. In addition, by supplying CO ₂ water to the back surface Wb of the substrate W, as shown in FIG. 6B , the charge entering the inside of the pattern 100 of the surface Wa of the substrate W is transferred to the pattern It can be taken out to the outer surface of (100). That is, by supplying CO ₂ water as a highly conductive liquid to the back surface Wb of the substrate W, the local charge arrangement on the surface Wa of the substrate W can be diffused. Since electric charges are accumulated on the front surface Wa (pattern 100) of the substrate W, even if CO ₂ water is supplied to the back surface Wb of the substrate W, Electrostatic discharges rarely occur.

In the highly conductive liquid supply step S3, if the liquid is supplied to the surface Wa of the substrate W in parallel with the supply of CO ₂ water to the back surface Wb of the substrate W, Electrostatic discharge may occur on the surface Wa of the substrate W due to the contact of the liquid on the surface Wa.

In the highly conductive liquid supply step S3, since the liquid is not supplied to the surface Wa of the substrate W in parallel with the supply of CO ₂ water to the back surface Wb of the substrate W, Generation of electrostatic discharge on the surface Wa can be suppressed or prevented more effectively.

Further, in the highly conductive liquid supplying step S3, the surface Wa of the substrate W is protected by the substrate facing surface 17a of the opposing member 6 while arranging the opposing member 6 at a proximate position. While doing so, CO ₂ water is supplied to the back surface Wb of the substrate W. Therefore, the return of the CO ₂ water from the back surface Wb of the substrate W to the front surface Wa side of the substrate W can be favorably suppressed or prevented.

In addition, an inert gas pipe (not shown) may be further connected to the upper surface nozzle 30 of the opposing member 6, and an inert gas valve (not shown) may be interposed to the inert gas pipe. In this case, an inert gas (for example, N ₂ gas, helium gas, argon gas, or a mixed gas thereof) is supplied to the inert gas piping from an inert gas supply source. The inert gas valve is controlled by the control device 3 . In this case, in the highly conductive liquid supply step S3, the control device 3 opens the inert gas valve in a state where the opposing member 6 is disposed in the proximate position, thereby opening the upper surface nozzle 30 through the inert gas pipe. is supplied with an inert gas, and the inert gas is discharged downward from the discharge port 30a toward the central portion of the surface Wa of the substrate W. As a result, an airflow of the inert gas flowing along the upper surface of the substrate W from the central portion toward the peripheral portion of the substrate W is formed. Therefore, the return of CO ₂ water from the back surface Wb of the substrate W to the front surface Wa side of the substrate W can be better suppressed or prevented.

When the first predetermined static elimination period (for example, about 60 seconds) elapses from the start of discharging the CO ₂ water, the control device 3 closes the CO ₂ draining valve 65 to discharge the lower surface from the nozzle 50. Dispensing of CO ₂ water is stopped. With this, the highly conductive liquid supplying step S3 ends.

After completion of the highly conductive liquid supply step S3, the control device 3 opens the lower suction valve 64. As a result, CO ₂ water is suctioned and removed from the interior of the lower common pipe 55 and the interior space of the lower connection portion 56 . After removing the CO ₂ water, the control device 3 closes the lower suction valve 64 .

Further, the control device 3 controls the opposing member elevating unit 27 to raise the opposing plate 17 from the proximate position and dispose it at an upper position as shown in FIG. 5B.

Next, as shown in FIG. 5B , the control device 3 applies a low-conductivity liquid (chemical liquid (for example, SC1 or SC2) to the front surface Wa of the substrate W and the back surface Wb of the substrate W. and a low-conductivity liquid supplying step (S4 in FIG. 4) of supplying DIW as a high-conductivity liquid (a liquid having lower conductivity than CO ₂ water, for example). Since DIW hardly contains ions, its conductivity is quite low. The electrical resistivity of the DIW supplied to the substrate W in the low-conductivity liquid supply step S4 is, for example, in the range of 10 MΩ·cm to 20 MΩ·cm, more specifically, about 18 MΩ·cm.

Specifically, the control device 3 opens the DIW upper valve 42 . As a result, DIW is discharged from the discharge port 30a of the upper surface nozzle 30 toward the central portion of the surface Wa (ie, upper surface) of the substrate W in a rotating state. The DIW adhering to the surface Wa of the substrate W receives the centrifugal force caused by the rotation of the substrate W and moves to the peripheral edge of the substrate W. As a result, a DIW liquid film covering the entire surface Wa of the substrate W is formed. In addition, the control device 3 opens the DIW lower valve 62. As a result, DIW is discharged from the discharge port 50a of the lower surface nozzle 50 toward the central portion of the lower surface Wb (ie, lower surface) of the substrate W in a rotating state. As a result, the DIW liquid film covering the entire surface of the back surface Wb of the substrate W is formed.

By supplying CO ₂ water to the back surface Wb of the substrate W, as shown in FIG. 6C , the electric charge drawn out to the outer surface of the pattern 100 is transferred to the surface Wa of the substrate W It is effectively removed by the supply of DIW. Further, since the conductive liquid DIW is supplied to the surface Wa of the substrate W after the amount of charge from the substrate W is reduced, occurrence of electrostatic discharge can be effectively suppressed or prevented. In addition, since the conductive liquid is DIW having a relatively low conductivity, the occurrence of electrostatic discharge can be suppressed or prevented more effectively.

Further, in parallel with the supply of DIW to the front surface Wa of the substrate W, DIW is supplied to the back surface Wb of the substrate W. In this way, the charge accumulated on the substrate W can be removed more effectively.

When the second predetermined static elimination period (for example, about 60 seconds) elapses from the start of DIW discharge, the control device closes the DIW upper valve 42 and the DIW lower valve 62, and the upper surface nozzle 30 The discharge of DIW and the discharge of DIW from the lower surface nozzle 50 are stopped. With this, the low-conductivity liquid supplying step S4 is ended.

After completion of the low-conductivity liquid supply process S4, the control device 3 opens the upper suction valve 44. In this way, DIW is sucked and removed from the inside of the upper common pipe 35 and from the inside space of the upper connection portion 36 . After removing the DIW, the controller 3 closes the upper suction valve 44 .

In addition, the controller 3 controls the spin motor 12 to increase the rotational speed of the spin base 14 to a predetermined liquid processing rotational speed (for example, about 500 rpm), thereby increasing the liquid processing rotational speed. keep it as

Next, as shown in FIG. 5C , the control device 3 supplies a chemical solution to the surface Wa of the substrate W to treat (clean) the surface Wa of the substrate W. The chemical solution supply step ( S5) of FIG. 4 is executed. In the chemical solution supplying step S5 according to this embodiment, the control device 3 supplies the chemical solution not only to the front surface Wa of the substrate W but also to the back surface Wb of the substrate W, The back surface Wb is processed (cleaned) (simultaneous double-sided processing). In the chemical liquid supply step S5, SC1 or SC2 is first supplied to the surface Wa of the substrate W. Since SC1 and SC2 contain a large amount of ions, they have high electrical conductivity. The electrical resistivity of SC1 supplied to the substrate W is on the order of 10 ⁻³ MΩ·cm, for example. In addition, the electrical resistivity of SC2 supplied to the substrate W is, for example, about 10 ⁻⁵ MΩ·cm.

SC1 and SC2 are liquids having conductivity higher than the number of CO ₂ . Therefore, in a state in which the surface Wa of the substrate W is not sufficiently discharged (a state in which a large amount of charge is accumulated on the surface Wa of the substrate W), the surface Wa of the substrate W When SC1 or SC2 is supplied to the surface (Wa) of the substrate (W), the surface (Wa) of the substrate (W) and the surface (Wa) of the substrate (W) come into contact with the surface (Wa) of the substrate (W). There is a possibility that an abrupt charge change occurs in Wa), and an electrostatic discharge may occur at or near the liquid contact position of the chemical liquid on the surface Wa of the substrate W.

However, since SC1 or SC2 is supplied to the surface Wa of the substrate W after the electric charge has been sufficiently removed by DIW and CO ₂ water, in the chemical solution supplying step S5, the surface Wa of the substrate W Electrostatic discharge does not occur when either SC1 or SC2 is contacted.

Following completion of the chemical solution supplying step S5, the controller 3 supplies DIW as a rinse liquid to the surface Wa of the substrate W to remove the chemical adhering to the surface Wa of the substrate W. A rinsing step (S6 in the figure) is carried out. In the rinsing step S6 according to this embodiment, DIW as a rinsing liquid is supplied not only to the front surface Wa of the substrate W but also to the back surface Wb of the substrate W, thereby cleaning the back surface Wb of the substrate W. processing (cleaning) (simultaneous double-sided processing).

By opening the DIW upper valve 42 and the DIW lower valve 62 by the controller 3, DIW is supplied to the front surface Wa and the rear surface Wb of the substrate W. Then, when a predetermined period elapses after the DIW upper valve 42 and the DIW lower valve 62 are opened, the controller 3 closes the DIW upper valve 42 and the DIW lower valve 62 . With this, the supply of DIW to the front surface Wa and the back surface Wb of the substrate W is stopped, and the rinsing step S6 is ended. Although DIW was used as the rinsing liquid, CO ₂ water may be used as the rinsing liquid.

After that, the control device 3 controls the opposing member elevating unit 27 to raise the opposing plate 17 to the retracted position.

Next, the control device 3 executes a drying process (S7 in FIG. 4 ). Specifically, the controller 3 raises the rotational speed of the substrate W up to a predetermined scattering speed (for example, several thousand rpm) higher than the liquid processing rotational speed, and moves the substrate W at the spraying speed. rotate As a result, a large centrifugal force is applied to the liquid on the substrate W, and the liquid adhering to the substrate W is scattered around the substrate W. In this way, the liquid is removed from the substrate W and the substrate W is dried.

When a predetermined period elapses from the start of the drying step S7, the controller 3 controls the spin motor 12 to stop the rotation of the spin chuck 5 (that is, the rotation of the substrate W) (FIG. 4 of S8). Thereafter, the substrate transfer robot CR enters the inner space of the processing chamber 4 and carries the processed substrate W out of the processing chamber 4 (S9 in FIG. 4 ). The substrate W is transferred from the substrate transfer robot CR to the indexer robot IR, and is stored in the substrate container C by the indexer robot IR.

7A to 7C are diagrams for explaining the contents of the chemical solution supplying step S5 included in the first substrate processing example. The chemical solution supplying step S5 is a step of cleaning the front surface Wa and the back surface Wb of the substrate W using the chemical solution.

Examples of the chemical solution supplying step S5 include a first chemical solution supplying step S51, a second chemical solution supplying step S52, and a third chemical solution supplying step S53.

The first chemical liquid supply step S51 includes an SC1 supply step of supplying SC1 to the front surface Wa and back surface Wb of the substrate W, and after the SC1 supply step, the front surface Wa and the back surface of the substrate W ( Wb) an intermediate rinsing step of supplying DIW (or CO ₂ water) as a rinsing liquid, and an SC2 supplying step of supplying SC2 to the front surface Wa and the back surface Wb of the substrate W after the intermediate rinsing process. and, after the SC2 supply step, an intermediate rinse step of supplying DIW (or CO ₂ water) as a rinse liquid to the front surface Wa and the back surface Wb of the substrate W, and after the intermediate rinse step, the substrate ( and a DHF supply step of supplying DHF (dilute hydrofluoric acid) to the front surface Wa and the rear surface Wb of W).

The second chemical liquid supply step S52 includes an SC2 supply step of supplying SC2 to the front surface Wa and back surface Wb of the substrate W, and after the SC2 supply step, the front surface Wa and the back surface of the substrate W ( Wb) an intermediate rinsing step of supplying DIW (or CO ₂ water) as a rinsing liquid, and an SC1 supplying step of supplying SC1 to the front surface Wa and the back surface Wb of the substrate W after the intermediate rinsing process. includes

The third chemical liquid supplying step S53 includes an SC1 supplying step of supplying SC1 to the front surface Wa and the back surface Wb of the substrate W.

In addition, the treatment liquid (chemical liquid or rinsing liquid (in this embodiment, DIW, CO ₂ In the case of supply of water, SC2)), after the discharge of the treatment liquid from the upper nozzle 30 or the lower nozzle 50 is finished, the corresponding upper suction valve 44 or lower suction valve 64 is opened, , DIW or CO ₂ water is suctioned and removed from the inside of the upper common pipe 35 or the lower common pipe 55 and from the inner space of the upper connected portion 36 or lower connected portion 56 .

From the foregoing, according to this embodiment, before supplying the chemical liquid (SC1 or SC2) to the substrate W, first, CO is applied to the back surface Wb of the substrate W instead of the front surface Wa of the substrate W. ₂ numbers are supplied. When the substrate W is charged, charges are accumulated on the front surface Wa of the substrate W, so even if CO ₂ water is supplied to the back surface Wb of the substrate W, the back surface of the substrate W Electrostatic discharge rarely occurs at (Wb). In addition, since the conductivity of the CO ₂ water is relatively high, the amount of charge stored in the substrate W can be effectively reduced by supplying the CO ₂ water to the back surface Wb of the substrate W.

In addition, by supplying CO ₂ water to the back surface Wb of the substrate W, the charge that has entered the inside of the pattern 100 on the surface Wa of the substrate W is transferred to the outer surface of the pattern 100. can be taken out

Then, DIW is supplied to the surface Wa of the substrate W. Thereby, the electric charge taken out to the outer surface of the pattern 100 can be effectively removed by DIW. Further, since the conductive liquid DIW is supplied to the surface Wa of the substrate W after the amount of charge from the substrate W is reduced, occurrence of electrostatic discharge can be effectively suppressed or prevented. In addition, since the conductive liquid is DIW having a relatively low conductivity, the occurrence of electrostatic discharge can be suppressed or prevented more effectively.

Then, at least the surface Wa of the substrate W after the electric charge has been sufficiently removed by DIW and CO ₂ water, the chemical solution supplying step S5 is executed. Therefore, in the chemical solution supplying step S5, the occurrence of electrostatic discharge accompanying the supply of SC1 or SC2 to the surface Wa of the substrate W can be suppressed or prevented.

As a result, it is possible to suppress or prevent the occurrence of electrostatic discharge accompanying the supply of liquid (DIW, CO ₂ water, chemical solution) to the surface Wa of the substrate W, so that the surface of the substrate W ( The occurrence of local defects in Wa) can be suppressed or prevented.

Next, the static elimination test is explained.

In the static elimination test, the sample is subjected to the substrate treatment method (cleaning treatment) according to Examples and Comparative Examples described below.

Example: A substrate W (semiconductor wafer. Outer diameter: 300 (mm)) having a pattern 100 (see FIG. 3B) disposed on the surface Wa is employed as a sample, and the surface Wa is facing upwards. It was held on the spin chuck 5 (see Fig. 2). With respect to the sample held by the spin chuck 5 and rotated, the first substrate treatment example (cleaning treatment) shown in FIG. 4 was performed using the processing unit 2 .

Comparative Examples 1 to 9: A substrate W (semiconductor wafer. Outer diameter: 300 (mm)) having a pattern 100 (see FIG. 3B) disposed on the surface Wa was employed as a sample, and the surface Wa was viewed from above. It was held on the spin chuck 5 (see Fig. 2) in the facing state. A cleaning treatment was performed using the processing unit 2 on the sample held on the spin chuck 5 and in a rotating state. Comparative Examples 1 to 9 are different from the example shown in FIG. 4 described above in the content of the static electricity elimination step (high conductivity liquid supply step S3 and low conductivity liquid supply step S4 in FIG. 4 ).

Comparative Example 1: A process corresponding to the high-conductivity liquid supply step S3 and a process corresponding to the low-conductivity liquid supply step S4 were not executed, respectively. That is, the chemical solution supplying step S5 is executed first.

Comparative Example 2: Instead of the highly conductive liquid supply step S3, a step of supplying CO ₂ water to the front surface Wa of the substrate W instead of to the back surface Wb of the substrate W is performed. A process corresponding to the low-conductivity liquid supplying process S4 is not executed. That is, after supplying the CO ₂ water to the surface Wa of the substrate W, the chemical solution supplying step S5 is executed.

Comparative Example 3: High conductivity liquid supply step S3 was executed. A process corresponding to the low-conductivity liquid supplying process S4 is not executed. That is, the chemical solution supplying process S5 is executed after the highly conductive liquid supplying process S3.

Comparative Example 4: Instead of the highly conductive liquid supply step S3, a step of supplying CO ₂ water to not only the back surface Wb of the substrate W but also the front surface Wa of the substrate W is performed. A process corresponding to the low-conductivity liquid supplying process S4 is not performed. That is, after supplying the CO ₂ water to the surface Wa of the substrate W, the chemical solution supplying step S5 is executed.

Comparative Example 5: A process corresponding to the highly conductive liquid supply process S3 was not performed. A process corresponding to the low-conductivity liquid supply process S4 is performed first. In this step, a step of supplying DIW to the front surface Wa of the substrate W instead of to the back surface Wb of the substrate W is performed.

Comparative Example 6: A process corresponding to the highly conductive liquid supply process S3 was not performed. A process corresponding to the low-conductivity liquid supply process S4 is performed first. In this step, a step of supplying DIW to the back surface Wb of the substrate W instead of the front surface Wa of the substrate W is performed.

Comparative Example 7: A process corresponding to the highly conductive liquid supply process S3 was not performed. The low-conductivity liquid supply process S4 is first executed.

Comparative Example 8: Instead of the highly conductive liquid supplying step S3, a step of supplying CO ₂ water to not only the back surface Wb of the substrate W but also the front surface Wa of the substrate W is performed. After this process, the low-conductivity liquid supply process S4 is executed.

Comparative Example 9: Instead of the highly conductive liquid supply step S3, a step of supplying CO ₂ water to the front surface Wa of the substrate W instead of to the back surface Wb of the substrate W is performed. After this process, the low-conductivity liquid supply process S4 is executed.

The test results are shown in FIG. 8 . In the examples, no electrostatic discharge occurred. In contrast, in Comparative Examples 1 to 9, traces of electrostatic discharge were observed in the central portion of the surface Wa of the substrate W. In Comparative Example 2, Comparative Example 4, Comparative Example 8, and Comparative Example 9, highly conductive CO ₂ water was initially supplied to the surface of the substrate W. It is thought that electrostatic discharge occurred in association with the supply of this CO ₂ water.

In Comparative Example 5 and Comparative Example 7, DIW having low conductivity was first supplied to the surface Wa of the substrate W. Even by this supply of DIW, the surface Wa of the substrate W (particularly, the charge that entered the inside of the pattern 100 as shown in FIG. 6A) is not sufficiently discharged, and therefore the subsequent substrate W ) is thought to have occurred with the supply of the chemical solution to the surface Wa.

In Comparative Example 1, Comparative Example 3, and Comparative Example 6, the chemical liquid having high conductivity was first supplied to the surface Wa of the substrate W. It is considered that the surface Wa of the substrate W is not sufficiently de-charged before the supply of the chemical liquid is started, and therefore, the electrostatic discharge occurs along with the supply of the chemical liquid to the surface Wa of the substrate W.

As mentioned above, although one embodiment of this invention was described, this invention can also be implemented in other forms.

9 is a flowchart for explaining a second substrate processing example executed by the processing unit 2 . The difference between the second substrate processing example shown in FIG. 9 and the first substrate processing example shown in FIG. 4 is that the low-conductivity liquid supplying step S11 is used instead of the low-conductive liquid supplying step S4 as the low-conductive liquid supplying step. . In the low-conductivity liquid supply step S11, DIW is supplied only to the front surface Wa of the substrate W, not to both surfaces Wa and back Wb of the substrate W.

In addition, in the first substrate processing example shown in FIG. 4 , in the low-conductivity liquid supply step S4, while supplying DIW as the low-conductivity liquid to the front surface Wa of the substrate W, the back surface Wb of the substrate W ) may be supplied with CO ₂ water as a highly conductive liquid.

10 is a flowchart for explaining a third substrate processing example executed by the processing unit 2 .

The difference between the third substrate processing example shown in FIG. 10 and the first substrate processing example shown in FIG. 4 is that after the low-conductive liquid supplying step S4 and before the chemical solution supplying step S5, in order to neutralize the substrate W, the substrate W ) on at least the front surface Wa (both the front surface Wa and the rear surface Wb (or only the front surface Wa)), a highly conductive liquid (a liquid having lower conductivity than the chemical liquid (eg, SC1, SC2)) The point is that the second highly conductive liquid supplying step S21 for supplying CO ₂ water as .

As indicated by the broken line in FIG. 2 , the phase mixing valve unit (UMV) connects the CO ₂ water phase pipe 40 connected to the phase connection part 36 and the CO ₂ water supply pipe 40 to open and close the CO ₂ water phase pipe 40 . An upper valve 45 may be further included. By opening the CO ₂ water valve 45 in a state where the other valves included in the upper liquid supply unit are closed, the CO ₂ water is supplied to the upper nozzle 30, whereby the CO ₂ water flows downward from the discharge port 30a. is discharged

According to this third substrate processing example, after DIW is supplied to the substrate W, CO ₂ water is supplied to at least the surface Wa of the substrate W during the period until the chemical liquid is supplied to the substrate W. In short, DIW → CO ₂ is supplied to the surface Wa of the substrate W in the order of number. Since DIW → CO ₂ water → chemical liquid and conductive liquid are supplied to the substrate step by step in the order of low conductivity, the substrate W is maintained in good condition while preventing the occurrence of electrostatic discharge caused by DIW or CO ₂ water. Static electricity can be eliminated, thereby effectively suppressing the occurrence of electrostatic discharge at the time of chemical solution supply.

In addition, as the chemical solution supplying step S5, processing of both sides (the front surface Wa and the back side Wb) of the substrate W using a chemical was cited as an example, but the chemical solution supplying step S5 is performed on one side of the substrate W (The surface (Wa) or the back surface (Wb)) may be treated using a chemical solution.

In addition, although SC1 or SC2 was exemplified as the chemical solution initially supplied to the surface Wa of the substrate W in the chemical solution supply step S5, other chemical solutions (ozone water or SPM (containing H ₂ SO ₄ and H ₂ O ₂ ) mixture), HF, etc.) may be used.

In addition, as a combination of a high conductivity liquid and a low conductivity liquid, a combination of CO ₂ water and DIW was exemplified, but besides, a combination of NH ₃ water and DIW, a combination of NH ₄ OH aqueous solution (1:100) and DIW, H ₂ SO ₄ A combination of aqueous solution and DIW, a combination of HCl aqueous solution (1:50 dilute hydrochloric acid) and DIW, a combination of HF aqueous solution (1:500 dilute hydrofluoric acid) and DIW, etc. can be illustrated.

Further, as examples of the first to third substrate processing, a cleaning process for cleaning the substrate W has been cited, but the present invention can also be applied to an etching process for etching the substrate W using an etchant.

Further, in the above-described embodiments, the case where the substrate processing apparatus 1 is a device for treating the surface of the substrate W made of a semiconductor wafer has been described, but the substrate processing apparatus is a substrate for a liquid crystal display device, an organic EL device, and the like. A device that processes substrates such as FPD (Flat Panel Display) substrates such as electroluminescence display devices, optical disk substrates, magnetic disk substrates, magneto-optical disk substrates, photomask substrates, ceramic substrates, and solar cell substrates. may be However, the effect of the present invention is particularly remarkably exhibited when the surface of the substrate W exhibits hydrophobicity.

Although the embodiments of the present invention have been described in detail, these are only specific examples used to clarify the technical content of the present invention, and the present invention should not be construed as being limited to these specific examples, and the scope of the present invention It is limited only by the appended claims.

This application corresponds to Japanese Patent Application No. 2018-009157 filed with the Japan Patent Office on January 23, 2018, and the entire disclosure of this application is incorporated herein by reference.

1: substrate processing device
3: control device
4: processing chamber
5: spin chuck (substrate holding unit)
30: upper nozzle (low conductive liquid supply unit)
37: DIW phase pipe (low conductivity liquid supply unit)
42: DIW upper valve (low conductive liquid supply unit)
50: bottom nozzle (high conductivity liquid supply unit)

Claims (11)

A method of treating a substrate by supplying a chemical solution to the surface of a substrate on which a pattern is formed,
a substrate holding step of holding the substrate;
a chemical solution supply step of supplying the chemical solution to the surface of the substrate on which the pattern is formed;
Prior to the chemical solution supply process, in order to remove charges accumulated on the outer surface of the pattern, a low conductivity liquid valve is opened, and a low conductivity liquid having a conductivity lower than that of the chemical liquid is supplied from a low conductivity liquid supply source to a low conductivity liquid nozzle. a low-conductivity liquid supply step of supplying the low-conductivity liquid from the low-conductivity liquid nozzle to the surface of the substrate on which the pattern is formed by supplying the low-conductivity liquid to the surface of the substrate;
Prior to the low-conductivity liquid supply process, a high-conductivity liquid having a conductivity lower than that of the chemical liquid and higher than that of the low-conductivity liquid is applied to a high-conductivity liquid different from that of the low-conductivity liquid valve in order to reduce the charge accumulated in the pattern. By opening a valve and supplying a high conductivity liquid nozzle from a high conductivity liquid source different from the low conductivity liquid source, the high conductivity liquid is supplied from the high conductivity liquid nozzle to the back surface of the substrate, which is opposite to the surface where the pattern is formed. A substrate processing method comprising a step of supplying a highly conductive liquid to a substrate. According to claim 1,
Parallel to the low-conductivity liquid supply step, the substrate processing method further comprises a step of supplying the low-conductivity liquid or the high-conductivity liquid to the back surface of the substrate to neutralize the substrate. According to claim 1 or 2,
Parallel to the highly conductive liquid supplying step, liquid is not supplied to the surface of the substrate. According to claim 1 or 2,
Parallel to the high-conductivity liquid supplying step, a proximity positioning process of arranging an opposing member having a substrate facing surface facing the entire surface of the substrate at a proximate position where the substrate facing surface is close to the surface of the substrate. Further comprising, a substrate processing method. According to claim 1 or 2,
After the low-conductivity liquid supplying process and prior to the chemical solution supplying process, further comprising a second high-conductivity liquid supplying process of supplying the high-conductivity liquid to at least the surface of the substrate to neutralize the substrate, method. According to claim 1 or 2,
The substrate holding process,
A substrate processing method comprising a step of holding a substrate by bringing a conductive portion formed using a conductive material into contact with a circumferential edge portion of the substrate. According to claim 1 or 2,
The substrate processing method of claim 1 , wherein the low-conductivity liquid comprises deionized water. According to claim 1 or 2,
The substrate processing method of claim 1 , wherein the highly conductive liquid comprises a liquid containing ions. a substrate holding unit holding a substrate having a pattern formed thereon;
a chemical solution supply unit for supplying a chemical solution having conductivity to the surface of the substrate held by the substrate holding unit;
a low conductivity liquid nozzle for supplying a low conductivity liquid having a conductivity lower than that of the chemical liquid to the surface of the substrate held by the substrate holding unit;
a low-conductivity liquid supply source for supplying the low-conductivity liquid to the low-conductivity liquid nozzle;
a low-conductivity liquid valve switching between supplying and stopping supply of the low-conductivity liquid from the low-conductivity liquid supply source to the low-conductivity liquid nozzle;
a high conductivity liquid nozzle for supplying a high conductivity liquid having a conductivity lower than that of the chemical liquid and higher than that of the low conductivity liquid to a back surface of the substrate held by the substrate holding unit, which is opposite to the front surface;
a high conductivity liquid supply source different from the low conductivity liquid supply source, connected to a high conductivity liquid valve to supply the high conductivity liquid to the high conductivity liquid nozzle;
a high conductivity liquid valve that switches supply and stop of supply of the high conductivity liquid to the high conductivity liquid nozzle from the high conductivity liquid supply source, the high conductivity liquid valve being different from the low conductivity liquid valve;
a control device for controlling the chemical liquid supply unit, the low-conductivity liquid valve, and the high-conductivity liquid valve;
In the control device, a chemical solution supplying step of supplying the chemical solution to the surface of the substrate on which the pattern is formed by the chemical solution supply unit, and removing charges accumulated on the outer surface of the pattern prior to the chemical solution supplying step. To do this, a low-conductivity liquid supplying step of opening the low-conductivity liquid valve to supply the low-conductivity liquid to the surface of the substrate on which the pattern is formed, by means of the low-conductivity liquid nozzle, and prior to the low-conductivity liquid supplying step, , In order to reduce the charge accumulated in the pattern, the high conductivity liquid valve is opened, and the high conductivity liquid is supplied to the back surface of the substrate, which is opposite to the surface where the pattern is formed, by the high conductivity liquid nozzle. A substrate processing apparatus that executes a highly conductive liquid supplying process. According to claim 9,
further comprising an opposing member having a substrate facing surface facing the entirety of the surface of the substrate being held by the substrate holding unit, the substrate facing surface being disposed in a proximate position proximate to the surface of the substrate. processing unit. According to claim 9 or 10,
The substrate processing apparatus according to claim 1 , wherein the substrate holding unit has a conductive pin formed using a conductive material as a holding pin for contacting and supporting a circumferential edge portion of the substrate.

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