TWI700743B - Substrate processing method and substrate processing device - Google Patents

Abstract

A substrate processing method, which is to supply a chemical solution to the surface of a patterned substrate to process the substrate; comprising: a substrate holding step, which holds the substrate; a chemical solution supply step, which supplies the above chemical solution to At least the above-mentioned surface of the substrate; a low-conductivity liquid supply step, which supplies a low-conductivity liquid with lower conductivity than the above-mentioned chemical liquid to the above-mentioned surface of the substrate before the above-mentioned chemical liquid supply step, in order to remove electricity from the substrate; and high The conductive liquid supplying step is to supply a highly conductive liquid having lower conductivity than the above-mentioned chemical solution and higher than the above-mentioned low-conductive liquid to the substrate in order to remove electricity from the substrate before the above-mentioned low-conductive liquid supplying step, It is not the above surface of the substrate, but the back surface on the opposite side to the above surface.

Description

Substrate processing method and substrate processing device

The present invention relates to a substrate processing method and a substrate processing apparatus for processing the surface of a substrate. The substrates to be processed include, for example, semiconductor wafers, substrates for liquid crystal display devices, organic EL (Electroluminescence) display devices, such as FPD (Flat Panel Display) substrates, optical disk substrates, and magnetic disks. Use substrates, substrates for magneto-optical disks, substrates for photomasks, ceramic substrates, substrates for solar cells, etc.

In the manufacturing steps of semiconductor devices, for example, a single-chip substrate processing device that processes substrates one by one is equipped with: a processing chamber; a rotating chuck, which holds the substrate substantially horizontally in the processing chamber, and makes the The substrate rotates; and a nozzle for spitting out the liquid medicine toward the surface of the substrate (the surface on which the pattern (element) is formed) rotated by the rotating chuck.

In substrate processing using such a substrate processing apparatus, for example, a chemical liquid is discharged from a nozzle toward the center of the surface of the substrate in a rotating state. The chemical liquid supplied to the center of the substrate surface receives centrifugal force generated by the rotation of the substrate, flows on the substrate surface toward the periphery, and spreads over the entire substrate surface. Thereby, the treatment by the chemical solution is performed on the entire surface of the substrate.

In the substrate carried into the processing chamber, there is a case where electric charge (ie, charged) is accumulated on the surface of the substrate through the previous steps (ion implantation, dry etching). When electric charge is accumulated on the surface of the substrate that is carried into the processing chamber, when the chemical liquid from the nozzle is applied to the surface of the substrate, the surface of the substrate contacts the chemical liquid and a drastic charge change occurs on the surface of the substrate. There is a risk of electrostatic discharge (arc) occurring at or near the location of the chemical solution. As a result, there are cases where local defects such as damage to the pattern (element) or perforation in the pattern occur on the surface of the substrate.

Herein, it is known in Patent Document 1 below that in order to prevent electrostatic discharge from occurring on the surface of the substrate at the start of the supply of the chemical solution, before the start of the supply of the chemical solution, an antistatic liquid (such as carbonic acid) having a lower conductivity than the chemical solution is used. Water) is supplied to the surface of the substrate.

[Prior Technical Literature] [Patent Literature]

[Patent Document 1] Specification of US Patent Application Publication No. 2009/211610

However, there is a case where the amount of charge of the substrate carried into the processing chamber is large. When carbonated water is used to remove electricity, the charge moves fast. Therefore, when the carbonated water reaches the substrate, electrostatic discharge may occur as the surface of the substrate contacts the carbonated water.

In addition, in order to gradually reduce the amount of charge of the substrate, it is also considered to supply an anti-static liquid (such as DIW (deionized water)) with a lower conductivity than carbonated water to the surface of the substrate, and after the supply, supply carbonated water to the substrate surface. However, when the amount of charge of the substrate is large, there is a possibility that electrostatic discharge may still occur even if DIW is supplied to the surface of the substrate.

That is, to suppress or prevent the occurrence of electrostatic discharge as the chemical liquid is supplied to the substrate Electricity, and it is necessary to suppress or prevent the occurrence of electrostatic discharge with the supply of static elimination fluid (carbonated water, DIW) to the substrate. In other words, it is necessary to suppress or prevent the occurrence of electrostatic discharge as the liquid is supplied to the substrate.

Here, the object of the present invention is to provide a substrate processing method and a substrate processing apparatus which can suppress or prevent the occurrence of electrostatic discharge with the supply of liquid to the surface of the substrate, thereby suppressing or preventing The occurrence of local defects.

The present invention provides a substrate processing method that supplies a chemical solution to the surface of a patterned substrate to process the substrate. The method includes: a substrate holding step, which holds the substrate; and a chemical solution supply step, which combines the above-mentioned chemical The liquid is supplied to at least the above surface of the substrate; the low-conductivity liquid supply step, which before the above-mentioned chemical liquid supply step, in order to remove the electricity from the substrate, the surface of the substrate is supplied with a low-conductivity liquid with lower conductivity than the above-mentioned chemical liquid ; And a high-conductivity liquid supply step, which before the above-mentioned low-conductivity liquid supply step, in order to neutralize the substrate, and supply a high-conductivity liquid with lower conductivity than the aforementioned chemical solution and higher than the aforementioned low-conductivity liquid to In the substrate, it is not the above-mentioned surface of the substrate, but the back surface on the opposite side to the above-mentioned surface.

According to this method, before the supply of the chemical liquid to the substrate, first, the highly conductive liquid is supplied to the back surface of the substrate instead of to the surface of the substrate. When the substrate is charged, the charge is accumulated on the surface of the substrate (the element surface on which the element is formed). Therefore, even if the highly conductive liquid is supplied to the back surface of the substrate, almost no electrostatic discharge 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 accumulated on the substrate can be effectively reduced by supplying the low-conductive liquid to the back of the substrate.

In addition, by supplying a highly conductive liquid to the back of the substrate, The charge that enters the pattern on the surface of the substrate is pulled out to the outer surface of the pattern.

Next, the low-conductivity liquid is supplied to the surface of the substrate. Thereby, the electric charge that escapes 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, the occurrence of electrostatic discharge can be effectively suppressed or prevented. Moreover, since the conductive liquid is a low-conductivity liquid with low conductivity, it can further effectively suppress or prevent the occurrence of electrostatic discharge.

Next, a chemical solution is supplied to at least the surface of the substrate after the charge has been sufficiently removed by the low-conductivity liquid and the high-conductivity liquid. In this way, liquid chemical treatment is performed. Therefore, it is possible to suppress or prevent the occurrence of electrostatic discharge along with the supply of the chemical liquid to the surface of the substrate.

With this, it is possible to suppress or prevent the occurrence of electrostatic discharge as the liquid (low conductivity liquid, high conductivity liquid, chemical liquid) is supplied to the surface of the substrate, and therefore, it is possible to suppress or prevent local defects on the surface of the substrate. occur.

In one embodiment of the present invention, the substrate processing method further includes the step of supplying the low-conductivity liquid or the low-conductivity liquid to the back surface of the substrate in synchronization with the aforementioned low-conductivity liquid supply step to remove electricity from the substrate. The steps of the above highly conductive liquid.

According to this method, the low-conductivity liquid or the high-conductivity liquid is supplied to the back of the substrate in synchronization with the supply of the low-conductivity liquid to the surface of the substrate. Thereby, the charge accumulated on the substrate can be removed more effectively. Therefore, it is possible to further effectively suppress or prevent the occurrence of electrostatic discharge during the supply of chemical liquid.

In another embodiment of the present invention, in synchronization with the above-mentioned high-conductivity liquid supply step, no liquid is supplied to the surface of the substrate.

When the liquid is supplied to the surface of the substrate in synchronization with the supply of the highly conductive liquid to the back surface of the substrate, there is a possibility that electrostatic discharge may occur on the surface of the substrate by the liquid impinging on the surface of the substrate.

In contrast, according to this method, in synchronization with the supply of the highly conductive liquid to the back of the substrate, no liquid is supplied to the surface of the substrate. Thereby, it is possible to more effectively suppress or prevent the occurrence of electrostatic discharge on the surface of the substrate.

In one embodiment of the present invention, the above-mentioned substrate processing method further includes: an approaching position arranging step, which, in synchronization with the above-mentioned high-conductivity liquid supply step, will have a substrate facing surface facing the entire surface of the substrate. The facing member is arranged at a position where the facing surface of the substrate is close to the surface of the substrate.

According to this method, the substrate facing surface of the facing member is brought close to the substrate surface, that is, the substrate facing surface of the facing member protects the substrate surface, and the highly conductive liquid is supplied to the back surface of the substrate. Therefore, the intrusion of the highly conductive liquid from the back surface of the substrate toward the surface side of the substrate and the intrusion of the highly conductive liquid toward the surface side of the substrate can be favorably suppressed or prevented.

In still another embodiment of the present invention, the substrate processing method further includes: a second highly conductive liquid supply step for removing electricity from the substrate after the low conductivity liquid supply step and before the chemical solution supply step , And supply the highly conductive liquid to at least the surface of the substrate.

According to this method, after the low-conductivity liquid is supplied to the substrate until the chemical solution is supplied to the substrate, the high-conductivity liquid is supplied to at least the surface of the substrate. That is, the surface of the substrate is supplied in the order of low conductivity liquid→high conductivity liquid. Since the conductive liquid is supplied in the order of low conductivity liquid → high conductivity liquid → chemical solution, that is, the conductive liquid is supplied step by step from the one with lower conductivity, thus preventing low conductivity Electrostatic discharge caused by high-conductivity liquids and liquids can effectively remove electricity from the substrate. In addition, it can effectively suppress the occurrence of electrostatic discharge during the supply of chemical liquids.

In one embodiment of the present invention, the above-mentioned substrate holding step includes the step of bringing a conductive portion formed of a conductive material into contact with a peripheral portion of the substrate to thereby hold the substrate.

According to this method, the substrate can be satisfactorily neutralized via a low-conductivity liquid or a high-conductivity liquid.

In addition, the aforementioned low-conductivity liquid may also include deionized water. The above-mentioned highly conductive liquid may also include a liquid containing ions.

The present invention provides a substrate processing apparatus, which includes: a substrate holding unit that holds a substrate with a pattern formed on the surface; and a chemical liquid supply unit for supplying a substrate to the surface of the substrate held by the substrate holding unit. Conductive chemical solution; low-conductivity liquid supply unit for supplying a low-conductivity liquid with lower conductivity than the aforementioned chemical solution to the surface of the substrate held by the substrate holding unit; high-conductivity liquid supply unit , Which is used to supply a highly conductive liquid with lower conductivity than the above-mentioned chemical liquid and higher than the above-mentioned low-conductive liquid to the back surface of the substrate held by the substrate holding unit on the opposite side to the above-mentioned surface; and a control device , Which controls the chemical liquid supply unit, the low-conductivity liquid supply unit, and the high-conductivity liquid supply unit; the control device executes the following steps: a chemical liquid supply step, which supplies the chemical liquid to at least one of the substrates Surface; a low-conductivity liquid supply step, which supplies the low-conductivity liquid to the surface of the substrate before the above-mentioned chemical solution supply step, in order to remove electricity from the substrate; and a high-conductivity liquid supply step, which is in the low-conductivity Before the sexual liquid supply step, the above-mentioned highly conductive liquid is supplied to the substrate, not on the above-mentioned surface of the substrate, but on the back side opposite to the above-mentioned surface. surface.

According to this configuration, before the supply of the chemical liquid to the substrate, first, the highly conductive liquid is supplied to the back surface of the substrate, not to the surface of the substrate. When the substrate is charged, the charge is accumulated on the surface of the substrate (the element surface on which the element is formed). Therefore, even if the highly conductive liquid is supplied to the back surface of the substrate, almost no electrostatic discharge 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 accumulated on the substrate can be effectively reduced by supplying the low-conductive liquid to the back of the substrate.

In addition, by supplying the highly conductive liquid to the back surface of the substrate, the charges that enter the pattern on the surface of the substrate can be pulled out to the outer surface of the pattern.

Next, the low-conductivity liquid is supplied to the surface of the substrate. Thereby, the electric charge that escapes 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, the occurrence of electrostatic discharge can be effectively suppressed or prevented. Moreover, since the conductive liquid is a low-conductivity liquid with low conductivity, it can further effectively suppress or prevent the occurrence of electrostatic discharge.

Next, a chemical solution is supplied to at least the surface of the substrate after the charge has been sufficiently removed by the low-conductivity liquid and the high-conductivity liquid. In this way, liquid chemical treatment is performed. Therefore, it is possible to suppress or prevent the occurrence of electrostatic discharge along with the supply of the chemical liquid to the surface of the substrate.

By this, it is possible to suppress or prevent the occurrence of electrostatic discharge as the liquid (low conductivity liquid, high conductivity liquid, chemical liquid) is supplied to the surface of the substrate, and therefore, it is possible to suppress or prevent local defects on the surface of the substrate It happened.

In an embodiment of the present invention, the above-mentioned substrate processing apparatus further includes: an opposing member having the same size as the substrate held by the above-mentioned substrate holding unit The substrate facing surface facing the entire surface is arranged at a position close to the substrate facing the substrate facing surface.

According to this configuration, the substrate facing surface of the facing member can be brought close to the substrate surface, that is, the substrate facing surface of the facing member can protect the substrate surface, and the highly conductive liquid can be supplied to the back surface of the substrate. In this case, it is possible to well suppress or prevent the intrusion of the highly conductive liquid from the back surface of the substrate toward the surface side of the substrate, and the intrusion of the highly conductive liquid toward the surface side of the substrate.

In an embodiment of the present invention, the above-mentioned substrate holding unit has a conductive pin which is a holding pin contacting the peripheral portion of the support substrate and is formed of a conductive material.

According to this configuration, the substrate can be satisfactorily neutralized via a low-conductivity liquid or a high-conductivity liquid.

The above-mentioned and other objects, features, and effects of the present invention are made clear by referring to the accompanying drawings and describing the following embodiments.

1‧‧‧Substrate processing equipment

2‧‧‧Processing unit

3‧‧‧Control device

4‧‧‧Processing chamber

5‧‧‧Rotating Chuck

6‧‧‧Opposite member

7‧‧‧The next wall

12‧‧‧Rotating motor

13‧‧‧Lower rotation axis

14‧‧‧Rotating base

14a‧‧‧Top

15‧‧‧Clamping pin

17‧‧‧Opposite plate

17a‧‧‧Substrate facing surface

18‧‧‧Upper rotation axis

22‧‧‧Support arm

27‧‧‧Opposite member lifting unit

30‧‧‧Top nozzle

30a‧‧‧Exit

31‧‧‧The first upper supply unit

32‧‧‧The second upper supply unit

33‧‧‧3rd Upper Supply Unit

35‧‧‧Shanghai Common Piping

36‧‧‧Upper connecting part

37‧‧‧DIW upper piping

38‧‧‧SC2 upper piping

39‧‧‧Upper suction piping

40‧‧‧CO ₂ water piping

42‧‧‧DIW upper valve

43‧‧‧SC2 upper valve

44‧‧‧Upper suction valve

45‧‧‧CO ₂ water valve

46‧‧‧SC1 upper piping

47‧‧‧SC1 Upper Valve

48‧‧‧HF upper piping

49‧‧‧HF Upper Valve

50‧‧‧Below nozzle

50a‧‧‧Exit

51‧‧‧The first lower supply unit

52‧‧‧The second lower supply unit

53‧‧‧3rd lower supply unit

55‧‧‧Common piping

56‧‧‧Lower connecting part

57‧‧‧DIW lower piping

58‧‧‧SC2 lower piping

59‧‧‧Down suction piping

60‧‧‧CO ₂ underwater piping

62‧‧‧DIW lower valve

63‧‧‧SC2 lower valve

64‧‧‧Lower suction valve

65‧‧‧CO ₂ underwater valve

66‧‧‧SC1 lower piping

67‧‧‧SC1 Lower Valve

68‧‧‧HF lower piping

69‧‧‧HF Lower Valve

100‧‧‧Pattern

101‧‧‧Construct

300‧‧‧OD

A1‧‧‧Rotation axis

C‧‧‧Substrate Organizer

CR‧‧‧Board transfer robot

DMV‧‧‧Lower mixing valve unit

IR‧‧‧Index Robot

LP‧‧‧Load port

T‧‧‧Film thickness

UMV‧‧‧Upper Mixing Valve Unit

W‧‧‧Substrate

W1‧‧‧Line width

W2‧‧‧Gap

Wa‧‧‧surface

Wb‧‧‧Back

FIG. 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.

3A and 3B are block diagrams for explaining the electrical configuration of the main parts of the substrate processing apparatus and enlarged cross-sectional views showing the surface of the substrate to be processed by the substrate processing apparatus.

Fig. 4 is used to illustrate the first example of substrate processing performed by the above processing unit flow chart.

5A to 5C are schematic views of the substrate when each step of the above-mentioned first substrate processing example is performed horizontally.

6A to 6C are diagrams for explaining the change in the charged state of the substrate in each step of the above-mentioned first substrate processing example.

7A to 7C are diagrams for explaining the contents of the chemical liquid supply step included in the first substrate processing example.

Figure 8 is a graph showing the test results of the static elimination test.

FIG. 9 is a flowchart for explaining a second example of substrate processing performed by the above-mentioned processing unit.

FIG. 10 is a flowchart for explaining a third substrate processing example executed by the above-mentioned processing unit.

FIG. 1 is a schematic view of a substrate processing apparatus 1 according to an embodiment of the present invention viewed from above. The substrate processing device 1 is a single-chip device that processes substrates W such as silicon wafers one by one. In this embodiment, the substrate W is a disc-shaped substrate. The substrate processing apparatus 1 includes: a plurality of processing units 2 for processing substrates W with processing liquid and eluent; a load port LP, which houses a substrate container, and the substrate container is stored in the processing unit 2 A plurality of substrates W to be processed; an index robot IR and a substrate transport robot CR, which transport the substrate W between the load port LP and the processing unit 2; and a control device 3, which controls the substrate processing device 1. The index robot IR transfers the substrate W between the substrate storage device and the substrate transfer robot CR. The substrate transfer robot CR transfers the substrate W between the index robot IR and the processing unit 2. The plural processing units 2 have, for example, the same configuration.

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

The processing unit 2 includes: a box-shaped processing chamber 4; a rotating chuck (substrate holding unit) 5, which holds a substrate W in a horizontal position in the processing chamber 4 so that the substrate W passes through the center of the substrate W The vertical axis of rotation A1 rotates; the upper liquid supply unit is used to supply liquid (treatment) to the upper surface of the substrate W (the surface of the substrate W (pattern formation surface) Wa (see FIG. 5A, etc.)) held on the rotating chuck 5. Liquid (chemical solution and eluent) and anti-static liquid); a lower liquid supply unit for supplying liquid to the underside of the substrate W held in the spin chuck 5 (the back surface Wb of the substrate W (see FIG. 5A, etc.)) (Processing liquid (chemical solution and eluent) and anti-static liquid); the opposite member 6, which faces the substrate W held on the rotating chuck 5, and separates the space above the substrate W from the ambient gas surrounding it In the shield; and a cylindrical processing cup (not shown), which surrounds the side of the rotating chuck 5.

The processing chamber 4 includes a box-shaped partition wall 7 which houses a rotating chuck 5 and the like.

As the rotary chuck 5, a clamping chuck which clamps the substrate W in the horizontal direction and holds the substrate W horizontally is used. Specifically, the rotating chuck 5 includes: a rotating motor (rotating unit) 12; a lower rotating shaft 13, which is integrated with the drive shaft of the rotating motor 12; and a disc-shaped rotating base 14, which is approximately horizontal The ground is installed on the upper end of the lower rotating shaft 13. The lower rotating shaft 13 is formed using a conductive material. The lower rotating shaft 13 is grounded.

The rotating base 14 includes a horizontal circular upper surface 14a, and the upper surface 14a has an outer diameter larger than that of the substrate W. The rotating base 14 is formed using a conductive material. On the upper surface 14a, a plurality of (3 or more, for example, 6) clamping pins 15 are arranged on the peripheral edge portion thereof. On the upper peripheral edge of the rotating base 14, a plurality of clamping pins 15 is arranged on a circumference corresponding to the outer peripheral shape of the substrate W with appropriate intervals, for example, at equal intervals. The clamping pin 15 is a so-called conductive pin formed using a conductive material.

As described above, the lower rotating shaft 13, the rotating base 14, and the clamping pin 15 are respectively formed of conductive materials (for example, carbon-containing conductive materials, metal materials), and the lower rotating shaft 13 is grounded. Therefore, when a conductive liquid (low-conductivity liquid, high-conductivity liquid, and chemical solution described later) is supplied to the surface or back of the substrate W held on the spin chuck 5, the substrate W is passed through the liquid. In addition to electricity.

The opposing member 6 includes an opposing plate 17 and an upper surface nozzle 30 penetrating the center of the opposing plate 17 in the vertical direction. The opposing plate 17 has a circular substrate opposing surface 17a arranged horizontally, and its lower surface faces the upper surface of the substrate W in its entirety.

In this embodiment, the upper surface nozzle 30 functions as a central axis nozzle. The upper nozzle 30 is arranged above the rotating chuck 5. The upper nozzle 30 is supported by the support arm 22. The upper nozzle 30 cannot rotate relative to the support arm 22. The upper nozzle 30 is raised and lowered together with the opposite plate 17 and the support arm 22. The upper surface nozzle 30 is formed with a discharge port 30a facing the center portion of the upper surface of the substrate W held by the spin chuck 5 at its lower end.

The supporting arm 22 is coupled with an opposite member lifting unit 27 including an electric motor, a ball screw, and the like. The facing member raising and lowering unit 27 raises and lowers the facing member 6 (the facing plate 17 and the upper rotating shaft 18) and the upper nozzle 30 together with the support arm 22 in the vertical direction.

The opposite member lifting unit 27 makes the opposite plate 17 at the close position (the position shown by the two-dot chain line in FIG. 2, also refer to FIG. 5A) and the retracted position (the position shown by the solid line in FIG. 2) Up and down, the approaching position is the substrate facing surface 17a approaching The position held on the upper surface of the substrate W of the spin chuck 5, and the retracted position is a position where the closer position is largely retracted upward. The facing member lifting unit 27 can hold the facing plate 17 in the approaching position (the position shown in FIG. 5A), the upper position (the position shown in FIGS. 5B and 5C), and the retracted position. The approaching position is a position where the substrate facing surface 17a and the upper surface of the substrate W are arranged at a slight interval (for example, about 0.3 mm). The upper position is a position where the distance between the substrate facing surface 17a and the upper surface of the substrate W is larger than the close position and smaller than the retreat position.

The upper liquid supply unit includes an upper surface nozzle 30 and a first upper supply unit 31, a second upper supply unit 32, and a third upper supply unit 33 that supply various processing liquids to the upper surface nozzle 30.

The first upper supply unit 31 includes an upper common pipe 35 having one end connected to the upper nozzle 30 and an upper mixing valve unit UMV connected to the other end of the upper common pipe 35. The upper mixing valve unit UMV includes an upper connecting portion 36 for transferring liquid to the upper common pipe 35 and a plurality of valves. A circulation space for liquid to circulate is formed inside the upper connecting portion 36. The upper mixing valve unit UMV system further includes the DIW upper pipe 37, the SC2 upper pipe 38, and the upper suction pipe 39 respectively connected to the upper connecting portion 36. The plural valve systems included in the upper mixing valve unit UMV include the DIW upper valve 42 for opening and closing the DIW upper piping 37, the SC2 upper valve 43 for opening and closing the SC2 upper piping 38, and the upper suction piping 39. Upper suction valve 44 opened and closed.

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

The pipe 38 on SC2 is supplied with SC2 (a mixed liquid containing HCl and H ₂ O ₂ ) from the SC2 supply source. The SC2 upper valve 43 is opened in a state of being closed to other valves included in the upper liquid supply unit, and 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, a jet suction device. The jet suction device includes a vacuum generator and aspirator. In the operating state of the suction device, the inside of the suction device is decompressed and the inside of the upper suction pipe 39 is sucked. As a result, the operation of the suction device is effective. In the state where the operation of the suction device is activated and the other valve included in the upper liquid supply unit is closed, the upper suction valve 44 is opened to suck the inside of the upper suction pipe 39, and The liquid in the inner space (circulation space) of the upper connecting portion 36 and the liquid in 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 nozzle 30 and an SC1 upper valve 47 interposed on the SC1 upper pipe 46. The pipe 46 on SC1 is supplied with SC1 (a mixed liquid containing NH ₄ OH and H ₂ O ₂ ) from the SC1 supply source. The SC1 upper valve 47 is opened in a state of closing other valves included in the upper liquid supply unit, and SC1 is supplied to the upper nozzle 30, whereby SC1 is discharged downward from the discharge port 30a.

The third upper supply unit 33 includes an HF upper pipe 48 connected to the upper nozzle 30 and an HF upper valve 49 interposed on the HF upper pipe 48. The pipe 48 on the HF is supplied with HF from the HF supply source. The upper HF valve 49 is opened in a state of being closed with other valves included in the upper liquid supply unit, and 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 diluted hydrofluoric acid (DHF).

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

The lower liquid supply unit includes a lower nozzle 50 and a first lower supply unit 51, a second lower supply unit 52, and a third lower supply unit 53 that supply various processing liquids to the lower nozzle 50.

The first lower supply unit 51 includes a lower common pipe 55 having one end connected to the lower 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 part 56 for conveying liquid to the lower common pipe 55 and a plurality of valves. A circulation space for liquid to circulate is formed inside the lower connecting portion 56. The lower mixing valve unit DMV system further includes a DIW lower pipe 57, an SC2 lower pipe 58, a CO ₂ underwater pipe 60, and a lower suction pipe 59, which are connected to the lower connecting portion 56, respectively. The 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 the CO ₂ underwater pipe 60 The CO ₂ underwater valve 65 that opens and closes, and the lower suction valve 64 that opens and closes the lower suction pipe 59.

Piping 57 under the DIW is supplied with DIW from a DIW supply source. The DIW lower valve 62 is opened in a state where other valves included in the lower mixing valve unit DMV are closed, and DIW is supplied to the lower nozzle 50, whereby the DIW is discharged upward from the discharge port 50a.

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

In underwater pipes 60 CO _2, CO ₂ supplied with water from a water supply source of CO _2. By opening the CO ₂ underwater valve 65 in a state where other valves included in the lower liquid supply unit are closed, CO ₂ water is supplied to the lower nozzle 50, whereby the CO ₂ water is discharged upward from the discharge port 50a.

A suction device (not shown) is connected to the downstream end of the lower suction pipe 59. The suction device is, for example, a jet suction device. The jet suction device includes a vacuum generator and aspirator. In the operating state of the suction device, the inside of the suction device is decompressed and the inside of the lower suction pipe 59 is sucked. As a result, the operation of the suction device is effective. In the state where the operation of the suction device is activated, and the other valve included in the lower liquid supply unit is closed, the lower suction valve 64 is opened to suck the inside of the lower suction pipe 59, The liquid in the inner space (circulation space) of the lower connecting portion 56 and the liquid in the lower common pipe 55 are sucked by the suction device.

The second lower supply unit 52 includes an SC1 lower pipe 66 connected to the lower nozzle 50 and an SC1 lower valve 67 interposed between the SC1 lower pipe 66. The SC1 lower pipe 66 is supplied with SC1 from the SC1 supply source. The SC1 lower valve 67 is opened in a state where other valves included in the lower liquid supply unit are closed, and SC1 is supplied to the lower 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 nozzle 50 and an HF lower valve 69 interposed between the HF lower pipe 68. The HF lower pipe 68 is supplied with HF from an HF supply source. The lower HF valve 69 is opened in a state where other valves included in the lower liquid supply unit are closed, and 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 diluted hydrofluoric acid (DHF).

In this embodiment, the lower nozzle 50, the CO ₂ underwater piping 60, and the CO ₂ underwater valve 65 constitute a highly conductive liquid supply unit.

FIG. 3A is a block diagram for explaining the electrical configuration of the 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, a hard disk drive, and an input/output unit. The program executed by the arithmetic unit is stored in the storage unit.

In addition, the rotation motor 12, the facing member elevating unit 27, and the like are connected to the control device 3 as a control target. The control device 3 controls the operation of the rotation motor 12, the facing member lifting unit 27, and the like in accordance with a predetermined program.

In addition, the control device 3 controls the DIW upper valve 42, SC2 upper valve 43, upper suction valve 44, SC1 upper valve 47, HF upper valve 49, DIW lower valve 62, and SC2 lower valve 63 in accordance with a predetermined program. , The lower suction valve 64, the CO ₂ underwater valve 65, the SC1 lower valve 67, and the HF lower valve 69 are opened and closed.

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

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

In addition, the pattern 100 may also be a line pattern formed by fine grooves repeatedly arranged. In addition, the pattern 100 can also be formed by the film being provided with a plurality of micropores (voids or pores).

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

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

4 is a flowchart for explaining the content of the first substrate processing example executed in the processing unit 2. 5A to 5C are schematic views of the substrate when each step of the first substrate processing example is performed horizontally. 6A to 6C are diagrams for explaining the change in the charged state of the substrate W in each step of the first substrate processing example.

With reference to FIGS. 1 to 4, the first substrate processing example will be described. 5A to 6C are appropriately described. The first substrate treatment example is a cleaning treatment for removing foreign matter (particles) from the surface of the substrate W. The second substrate processing example and the third substrate processing example described later are the same, and are cleaning processing for removing foreign matter from the surface of the substrate W.

The unprocessed substrate W (for example, a circular substrate with a diameter of 300 mm) is moved from the substrate storage C to the processing unit 2 by the indexing robot IR and the substrate transfer robot CR, and then moved into the processing chamber 4 to transfer the substrate W its surface Wa (pattern formation surface, element formation surface, refer to Figure 3B, etc.) facing upwards is transferred to the rotating chuck 5, and the substrate W is held on the rotating chuck 5 (substrate holding step, Figure 4 S1: Load the substrate W). In this state, the back surface Wb (see FIG. 6A etc.) of the substrate W faces downward.

The substrate carried into the internal space of the processing chamber 4 may be charged (that is, charged) on the substrate W due to the previous steps (ion implantation, dry etching). When the substrate W is charged, as shown in FIG. 6A, the charge is mainly accumulated on the surface Wa of the substrate W. More specifically, the charge enters the pattern 100 on the surface Wa of the substrate W. When the chemical solution (the conductive chemical solution of SC1, SC2, etc.) is supplied to the substrate W, the surface Wa of the substrate W contacts the chemical solution and a drastic charge change occurs on the surface Wa of the substrate W. There is a risk of electrostatic discharge occurring at or near the liquid loading position. As a result, there are cases where local defects such as damage to the pattern 100 and perforations in the pattern 100 occur on the surface Wa of the substrate W. Therefore, before the chemical liquid supply step S5, in order to neutralize the substrate W, the high-conductivity liquid supply step S3 and the low-conductivity liquid supply step S4 are executed.

After the substrate transfer robot CR retreats to the processing unit 2, the control device 3 controls the rotation motor 12 to increase the rotation speed of the rotation base 14 to a predetermined static elimination rotation speed (about less than 500 rpm, for example, about 200 rpm), and maintain it At this static elimination rotation speed (S2 in FIG. 4: rotation of the substrate W starts).

In addition, the control device 3 controls the facing member raising and lowering unit 27 so that the facing plate 17 is lowered from the retracted position and arranged at the close position as shown in FIG. 5A.

When the rotation of the substrate W reaches the static elimination rotation speed, the control device 3 executes the high-conductivity liquid supply step (S3 in Fig. 4) as shown in FIG. 5A. The high-conductivity liquid supply step will be the high-conductivity liquid ( The CO ₂ water, which has a lower conductivity than the chemical solution (such as SC1 and SC2), is supplied to the back surface Wb of the substrate W instead of being supplied to the surface Wa of the substrate W. Since CO ₂ water contains ions, it has a certain degree of high conductivity. The resistivity of CO ₂ water supplied to the substrate W in the high-conductivity liquid supply step S3 (lower resistivity means higher conductivity) is, for example, in the range of 10 ^-6 MΩ‧cm~20MΩ‧cm, more specifically It is about 20MΩ‧cm~about 30MΩ‧cm.

Specifically, the control device 3 opens the CO ₂ underwater valve 65. Thereby, CO ₂ water is discharged from the discharge port 50a of the lower surface nozzle 50 toward the center portion of the back surface Wb (ie, the lower surface) of the substrate W in the rotating state. The CO ₂ water system impregnated on the back surface Wb of the substrate W is moved toward the periphery of the substrate W by the centrifugal force generated by the rotation of the substrate W. Thereby, a liquid film of CO ₂ water covering the entire back surface Wb of the substrate W is formed.

Since the conductivity of CO ₂ water is relatively high, by supplying CO ₂ water as a highly conductive liquid to the back surface Wb of the substrate W, the amount of electric 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 electric charge entering the inside of the pattern 100 on the surface Wa of the substrate W can be drawn to the outer surface of the pattern 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. Because electric charges are accumulated on the surface Wa (pattern 100) of the substrate W, even if CO ₂ water is supplied to the back surface Wb of the substrate W, almost no electrostatic discharge occurs on the back surface Wb of the substrate W.

In the high-conductivity liquid supply step S3, if the liquid is supplied to the surface Wa of the substrate W in synchronization with the supply of CO ₂ water to the back surface Wb of the substrate W, the liquid is present on the surface Wa of the substrate W. There is a risk of electrostatic discharge occurring on the surface Wa of the substrate W.

In the high-conductivity liquid supply step S3, the CO ₂ water is supplied to the back surface Wb of the substrate W in synchronization with the supply of the liquid to the surface Wa of the substrate W. Therefore, it is possible to more effectively suppress or prevent the liquid on the surface Wa of the substrate W. The occurrence of electrostatic discharge.

In addition, in the high-conductivity liquid supply step S3, the facing member 6 is arranged at a close position, that is, the surface Wa of the substrate W is protected by the substrate facing surface 17a of the facing member 6, and the other is facing the substrate W On the back side Wb supplies CO ₂ water. Therefore, the intrusion of CO ₂ water from the back surface Wb of the substrate W toward the surface Wa side of the substrate W can be well suppressed or prevented.

Furthermore, an inert gas piping (not shown) may be further connected to the nozzle 30 on the upper surface of the opposed member 6, and an inert gas valve (not shown) may be interposed in the inert gas piping. In this case, an inert gas (for example, N ₂ gas, helium, argon, or a mixed gas of these) is supplied to the inert gas pipe from the inert gas supply source. The inert gas valve is controlled by the control device 3. In this case, in the high-conductivity liquid supply step S3, the control device 3 opens the inert gas valve with the opposing member 6 arranged in the close position, and supplies inert gas to the upper nozzle 30 through the inert gas piping. The gas is discharged downward from the discharge port 30a toward the center of the surface Wa of the substrate W. Thereby, a flow of inert gas flowing from the center portion of the substrate W toward the peripheral edge portion is formed along the upper surface of the substrate W. Therefore, the intrusion of CO ₂ water from the back surface Wb of the substrate W toward the surface Wa side of the substrate W can be further suppressed or prevented.

When the preset first neutralization period (for example, about 60 seconds) has passed since the discharge of CO ₂ water, the control device 3 closes the CO ₂ underwater valve 65 to stop the discharge of CO ₂ water from the lower nozzle 50. With this, the highly conductive liquid supply step S3 ends.

After the high-conductivity liquid supply step S3 is completed, the control device 3 opens the lower suction valve 64. Thereby, CO ₂ water is sucked and removed from the inner space of the lower common pipe 55 and the inner space of the lower connecting portion 56. After the CO ₂ water is removed, the control device 3 closes the lower suction valve 64.

In addition, the control device 3 controls the opposite member lifting unit 27 to make The facing plate 17 rises from the close position, and is arranged at the upper position as shown in FIG. 5B.

Next, the control device 3 executes the low-conductivity liquid supply step (S4 in Fig. 4) as shown in FIG. 5B. The low-conductivity liquid supply step is to be used as a low-conductivity liquid (with a higher chemical liquid (such as SC1, SC2) ) And high-conductivity liquid (such as CO ₂ water, low-conductivity liquid) DIW is supplied to the surface Wa of the substrate W and the back surface Wb of the substrate W. Since DIW contains almost no ions, its conductivity is quite low. The resistivity of the DIW supplied to the substrate W in the low-conductivity liquid supply step S4 is, for example, in the range of 10MΩ‧cm to 20MΩ‧cm, more specifically about 18MΩ‧cm.

Specifically, the control device 3 opens the DIW upper valve 42. Thereby, DIW is discharged from the discharge port 30a of the upper surface nozzle 30 toward the center portion of the surface Wa (that is, the upper surface) of the substrate W in the rotating state. The DIW impinged on the surface Wa of the substrate W is moved toward the periphery of the substrate W by the centrifugal force generated by the rotation of the substrate W. Thereby, a liquid film of DIW covering the entire surface Wa of the substrate W is formed. In addition, the control device 3 opens the DIW lower valve 62. Thereby, DIW is discharged from the discharge port 50a of the lower surface nozzle 50 toward the center portion of the back surface Wb (ie, the lower surface) of the substrate W in the rotating state. Thereby, a liquid film of DIW covering the entire area of the back surface Wb of the substrate W is formed.

As shown in FIG. 6C, by supplying CO ₂ water to the back surface Wb of the substrate W, the charge drawn to the outer surface of the pattern 100 is effectively removed by the supply of DIW to the surface Wa of the substrate W. In addition, since the conductive liquid (DIW) is supplied to the surface Wa of the substrate W after the amount of charge is reduced from the substrate W, the occurrence of electrostatic discharge can be effectively suppressed or prevented. Moreover, since the conductive liquid is DIW with low conductivity, it can further effectively suppress or prevent the occurrence of electrostatic discharge.

In addition, in synchronization with supplying DIW to the front surface Wa of the substrate W, DIW is supplied to the back surface Wb of the substrate W. This can further effectively remove The electric charge of the plate W. When the preset second neutralization period (for example, about 60 seconds) has elapsed since the start of DIW discharge, the control device closes the DIW upper valve 42 and the DIW lower valve 62 to stop the DIW discharge from the upper nozzle 30 and DIW from the lower The nozzle 50 spit out. With this, the low-conductivity liquid supply step S4 ends.

After the low-conductivity liquid supply step S4 is completed, the control device 3 opens the upper suction valve 44. Thereby, DIW is sucked and removed from the inside of the upper common pipe 35 and the inner space of the upper connecting portion 36. After the DIW is removed, the control device 3 closes the upper suction valve 44.

In addition, the control device 3 controls the rotation motor 12 to increase the rotation speed of the rotation base 14 to a predetermined liquid treatment rotation speed (for example, about 500 rpm), and maintain the liquid treatment rotation speed.

Next, as shown in FIG. 5C, the control device 3 supplies the chemical liquid to the surface Wa of the substrate W, and executes the chemical liquid supply step of processing (cleaning) the surface Wa of the substrate W (S5 in FIG. 4). In the chemical solution supply step S5 of this embodiment, the control device 3 not only supplies the chemical solution to the surface Wa of the substrate W, but also supplies the chemical solution to the back surface Wb of the substrate W, and processes (cleans) the back surface Wb( Simultaneous treatment on both sides). In the chemical liquid supply step S5, SC1 or SC2 is supplied to the surface Wa of the substrate W first. SC1 and SC2 contain a large amount of ions, so they have high conductivity. The resistivity of SC1 supplied to the substrate W is, for example, in the order of 10 ^-3 MΩ·cm. In addition, the resistivity of SC2 supplied to the substrate W is, for example, about 10 ^-5 MΩ·cm.

SC1 and SC2 are liquids with higher conductivity than CO ₂ water. Therefore, when the surface Wa of the substrate W is not sufficiently de-charged (a state where a large amount of charge is accumulated on the surface Wa of the substrate W), SC1 or SC2 is supplied to the surface Wa of the substrate W, and then SC1 or SC2 faces the substrate When the surface Wa of W is deposited, the surface Wa of the substrate W is in contact with SC1 or SC2, and a drastic charge change occurs on the surface Wa of the substrate W, and there is a liquid deposit position on the surface Wa of the substrate W There is a risk of electrostatic discharge in or near it.

However, because SC1 or SC2 is supplied to the surface Wa of the substrate W after the charge has been sufficiently removed by DIW and CO ₂ water, in the chemical liquid supply step S5, SC1 or SC2 is deposited on the surface Wa of the substrate W When there is no electrostatic discharge.

After the chemical liquid supply step S5 is completed, the control device 3 supplies DIW as a rinsing liquid to the surface Wa of the substrate W, and performs a rinsing step of washing the chemical liquid attached to the surface Wa of the substrate W (FIG. 4 Of S6). In the rinsing step S6 of this embodiment, DIW as a rinsing liquid is supplied not only to the surface Wa of the substrate W but also to the back surface Wb of the substrate W, and the back surface Wb of the substrate W is processed (washed) (simultaneous double-sided processing) .

The control device 3 opens the DIW upper valve 42 and the DIW lower valve 62, thereby supplying DIW to the surface Wa and the back surface Wb of the substrate W. Next, when a predetermined period has elapsed after the DIW upper valve 42 and the DIW lower valve 62 are opened, the control device 3 closes the DIW upper valve 42 and the DIW lower valve 62. Thereby, 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 ends. Although DIW is used as the eluent, CO ₂ water can also be used as the eluent.

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

Next, the control device 3 executes the drying step (S7 in Fig. 4). Specifically, the control device 3 increases the rotation speed of the substrate W to a predetermined spin-off speed (for example, thousands of rpm) that is greater than the liquid processing spin speed, and causes the substrate W to be at the spin-off speed. Degree rotation. Thereby, a relatively large centrifugal force is applied to the liquid on the substrate W, and the liquid attached to the substrate W is thrown out to the periphery of the substrate W. In this way, the liquid is removed from the substrate W, and the substrate W is dried.

When a preset period has elapsed since the beginning of the drying step S7, the control device 3 controls the rotation motor 12 to stop the rotation of the spin chuck 5 (that is, the rotation of the substrate W) (S8 in FIG. 4). After that, 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 of FIG. 4). The substrate W is transferred from the substrate transfer robot CR to the index robot IR, and is stored in the substrate container C by the index robot IR.

7A to 7C are diagrams for explaining the contents of the chemical solution supply step S5 included in the first substrate processing example. The chemical liquid supply step S5 is a step of washing the surface Wa and the back surface Wb of the substrate W with chemical liquid.

As an example of the chemical solution supply step S5, there are a first chemical solution supply step S51, a second chemical solution supply step S52, and a third chemical solution supply step S53.

The first chemical liquid supply step S51 includes: an SC1 supply step, which supplies SC1 to the surface Wa and back surface Wb of the substrate W; an intermediate rinsing step, which applies to the surface Wa and back surface of the substrate W after the SC1 supply step Wb supplies DIW (or CO ₂ water) as rinsing liquid; SC2 supply step, after the intermediate rinsing step, supplies SC2 to the surface Wa and backside Wb of the substrate W; the intermediate rinsing step, which is in the SC2 After the supply step, DIW (or CO ₂ water) is supplied as a rinse solution to the surface Wa and back surface Wb of the substrate W; and a DHF supply step, which supplies DHF (diluted hydrofluoric acid) after the intermediate rinse step To the surface Wa and the back surface Wb of the substrate W.

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

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

In addition, when using the upper mixing valve unit UMV or the lower mixing valve unit DMV, the treatment liquid (chemical liquid or eluent (in this embodiment, DIW, CO ₂ water, SC2)) is supplied from the upper nozzle 30 or the lower nozzle 50) In this case, after the discharge of the processing liquid from the upper nozzle 30 or the lower nozzle 50 is completed, the corresponding upper suction valve 44 or lower suction valve 64 is opened, from the inside of the upper common pipe 35 or the lower common pipe 55, The inner space of the upper connecting portion 36 or the lower connecting portion 56 sucks and removes DIW or CO ₂ water.

Based on the foregoing, according to this embodiment, before supplying the chemical solution (SC1 or SC2) to the substrate W, first, CO ₂ water is supplied to the back surface Wb of the substrate W, instead of CO ₂ water being supplied to the surface Wa of the substrate W. When the substrate W is charged, because the charge is accumulated on the surface Wa of the substrate W, even if CO ₂ water is supplied to the back surface Wb of the substrate W, there is almost no electrostatic discharge on the back surface Wb of the substrate W. situation. In addition, since the conductivity of CO ₂ water is relatively high, by supplying CO ₂ water to the back surface Wb of the substrate W, the amount of electric charge accumulated on the substrate W can be effectively reduced.

In addition, by supplying CO ₂ water to the back surface Wb of the substrate W, the electric charge entering the inside of the pattern 100 on the surface Wa of the substrate W can be pulled out to the outer surface of the pattern 100.

Next, DIW is supplied to the surface Wa of the substrate W. In this way, the charge drawn to the outer surface of the pattern 100 can be effectively removed by the DIW. In addition, Since the conductive liquid (DIW) is supplied to the surface Wa of the substrate W after the amount of charge is reduced from the substrate W, the occurrence of electrostatic discharge can be effectively suppressed or prevented. Moreover, since the conductive liquid is DIW with low conductivity, it can further effectively suppress or prevent the occurrence of electrostatic discharge.

Next, the chemical solution supply step S5 is performed to at least the surface Wa of the substrate W after the charge has been sufficiently removed by DIW and CO ₂ water. Therefore, in the chemical liquid supply step S5, it is possible to suppress or prevent the occurrence of electrostatic discharge when SC1 or SC2 is supplied to the surface Wa of the substrate W.

Thereby, it is possible to suppress or prevent the occurrence of electrostatic discharge along with the supply of liquid (DIW, CO ₂ water, chemical solution) to the surface Wa of the substrate W, so that local defects on the surface Wa of the substrate W can be suppressed or prevented It happened.

Next, the static elimination detection will be described.

In the static elimination test, the sample was subjected to the substrate processing method (cleaning treatment) of the following examples and comparative examples.

Example: A substrate W (semiconductor wafer, outer diameter 300 (mm)) with a pattern 100 (refer to FIG. 3B) arranged on the surface Wa was used as a sample, and held in a rotating chuck with the surface Wa facing upward 5 (Refer to Figure 2). For the sample held in the rotating chuck 5 in a rotating state, the processing unit 2 is used to execute the first substrate processing example (cleaning processing) shown in FIG. 4 described above.

Comparative Examples 1-9: A substrate W (semiconductor wafer, outer diameter 300 (mm)) with a pattern 100 (see FIG. 3B) arranged on the surface Wa was used as a sample, and the substrate W was held with the surface Wa facing upward Rotate the chuck 5 (refer to Figure 2). The sample held in the rotating chuck 5 in a rotating state is subjected to a washing treatment using the processing unit 2. The difference between Comparative Examples 1-9 and the above-mentioned embodiment shown in Figure 4 is the static elimination step The contents of (the high-conductivity liquid supply step S3 and the low-conductivity liquid supply step S4 in FIG. 4).

Comparative Example 1: The step corresponding to the high-conductive liquid supply step S3 and the step corresponding to the low-conductive liquid supply step S4 were not performed. That is, the chemical liquid supply step S5 is executed first.

Comparative Example 2: The step of supplying CO ₂ water to the surface Wa of the substrate W instead of supplying CO ₂ water to the back surface Wb of the substrate W is performed instead of the high-conductivity liquid supply step S3. The step corresponding to the low-conductivity liquid supply step S4 is not performed. That is, after CO ₂ water is supplied to the surface Wa of the substrate W, the chemical solution supply step S5 is executed.

Comparative example 3: Highly conductive liquid supply step S3 is performed. The step corresponding to the low-conductivity liquid supply step S4 is not performed. That is, after the highly conductive liquid supply step S3, the chemical liquid supply step S5 is executed.

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

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

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

Comparative Example 7: The step corresponding to the highly conductive liquid supply step S3 was not performed. Initially, the low-conductivity liquid supply step S4 is performed.

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

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

The test results are shown in Figure 8. In the examples, no electrostatic discharge occurred. In contrast, in Comparative Examples 1 to 9, traces of electrostatic discharge were observed in the center of the surface Wa of the substrate W. In Comparative Example 2, Comparative Example 4, Comparative Example 8, and Comparative Example 9, CO ₂ water having high conductivity was initially supplied to the surface of the substrate W. It can be inferred that electrostatic discharge occurs with the supply of CO ₂ water.

In Comparative Example 5 and Comparative Example 7, DIW having low conductivity was initially supplied to the surface Wa of the substrate W. Due to the supply of DIW, the surface Wa of the substrate W (especially the charge that enters the pattern 100 as shown in FIG. 6A) is not sufficiently neutralized. Therefore, it can be inferred that the surface Wa of the substrate W followed by Electrostatic discharge occurs due to the supply of liquid medicine on the surface Wa.

In Comparative Example 1, Comparative Example 3, and Comparative Example 6, a chemical solution having high conductivity was initially supplied to the surface Wa of the substrate W. Before the supply of the chemical solution starts, the surface Wa of the substrate W is not sufficiently neutralized. Therefore, it can be inferred that electrostatic discharge occurs with the supply of the chemical solution to the surface Wa of the substrate W.

Above, one embodiment of the present invention has been described, but the present invention can also be implemented in other forms.

FIG. 9 is a flowchart for explaining a second example of substrate processing performed 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 etc. is that the low-conductivity liquid supply step S11 is used as the low-conductivity liquid supply step instead of the low-conductivity liquid supply Step S4. In the low-conductivity liquid supply step S11, DIW is supplied only to the surface Wa of the substrate W, and DIW is not supplied to both the surface Wa and the back surface 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, it is also possible to supply DIW as a low-conductivity liquid on the surface Wa facing the substrate W while facing the back surface of the substrate W Wb supplies CO ₂ water as a highly conductive liquid.

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

The third substrate processing example shown in FIG. 10 is different from the first substrate processing example shown in FIG. 4, etc., in that the second highly conductive liquid supply step S21 is performed, and the second highly conductive liquid supply step S21 is set to low After the conductive liquid supply step S4 and before the chemical liquid supply step S5, in order to eliminate the charge of the substrate W, the supply of the substrate W to at least the surface Wa (both the surface Wa and the back surface Wb (or only the surface Wa)) is high. Conductive liquid (liquid with lower conductivity than chemical liquid (such as SC1, SC2)) CO ₂ water.

As shown in FIG. 2 as shown in phantom, the mixing valve unit further comprises UMV also connected to the connecting portion 36 of the water pipe 40 CO.'S _2, and CO.'S ₂ to the water pipe 40 to open and close the water valve 45 CO.'S _2. The CO ₂ water valve 45 is opened while the other valve included in the upper liquid supply unit is closed, and CO ₂ water is supplied to the upper nozzle 30, whereby CO ₂ water is discharged downward from the discharge port 30a.

According to this third substrate processing example, after the DIW is supplied to the substrate W until the chemical solution is supplied to the substrate W, CO ₂ water is supplied to at least the surface Wa of the substrate W. That is, the surface Wa of the substrate W is supplied in the order of DIW→CO ₂ water. Since the conductive liquid is supplied to the substrate step by step in the order of DIW→CO ₂ water→chemical solution, starting from the one with lower conductivity, it can prevent electrostatic discharge caused by DIW and CO ₂ water. The substrate W is satisfactorily neutralized, thereby effectively suppressing the occurrence of electrostatic discharge during the supply of the chemical solution.

In addition, as the chemical liquid supply step S5, although the case where both sides (the front surface Wa and the back surface Wb) of the substrate W are treated with the chemical liquid has been cited as an example, the chemical liquid supply step S5 may also be the one side ( Surface Wa or back Wb).

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

In addition, as a combination of high conductivity liquid and low conductivity liquid, although the combination of CO ₂ water and DIW has been exemplified, the combination of NH ₃ water and DIW, NH ₄ OH aqueous solution (1:100) and The combination of DIW, the combination of H ₂ SO ₄ aqueous solution and DIW, the combination of HCl aqueous solution (1:50, dilute hydrochloric acid) and DIW, the combination of HF aqueous solution (1:500, dilute hydrofluoric acid) and DIW, etc.

In addition, as the first to third substrate processing examples, although the cleaning process for cleaning the substrate W has been cited as an example, the present invention can also be applied to an etching process for etching the substrate W using an etchant.

In addition, in the above-mentioned embodiment, although the case where the substrate processing apparatus 1 is an apparatus for processing the surface of a substrate W formed of a semiconductor wafer has been described, the substrate processing apparatus may also be a substrate for liquid crystal display devices. ,organic EL (electroluminescence) display devices, such as FPD (Flat Panel Display) substrates, optical disk substrates, magnetic disk substrates, magneto-optical disk substrates, photomask substrates, ceramic substrates, solar cell substrates Such as the substrate processing equipment. However, the effect of the present invention can be particularly prominently exhibited when the surface of the substrate W is rendered hydrophobic.

The embodiments of the present invention have been described in detail, but these are only specific examples used to clearly illustrate the technical content of the present invention. The present invention should not be construed as limiting these specific examples. The scope is limited only by the scope of the attached patent application.

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

Claims (11)

A substrate processing method, which is to supply a chemical solution to the surface of a patterned substrate to process the substrate; comprising: a substrate holding step, which holds the substrate; a chemical solution supply step, which supplies the above chemical solution to At least the above-mentioned surface of the substrate; a low-conductivity liquid supply step, which before the above-mentioned chemical liquid supply step, in order to remove the electric charge accumulated on the outer surface of the pattern formed on the above-mentioned surface of the substrate, the above-mentioned surface of the substrate is supplied with conductivity A low-conductivity liquid with lower conductivity than the above-mentioned chemical solution; and a high-conductivity liquid supply step, which before the above-mentioned low-conductivity liquid supply step, in order to reduce the charge accumulated in the pattern formed on the surface of the substrate and enter The charge to the inside of the pattern is drawn to the outer surface of the pattern, and a highly conductive liquid with lower conductivity than the chemical solution and higher than the low conductivity liquid is supplied to the substrate, not the surface of the substrate , And is the back side opposite to the above surface. The substrate processing method of claim 1, which further includes the step of supplying the low-conductivity liquid or the aforementioned high-conductivity liquid to the back surface of the substrate in synchronization with the aforementioned low-conductivity liquid supply step to remove electricity from the substrate. Conductive liquid step. The substrate processing method of claim 1 or 2, wherein, in synchronization with the high-conductivity liquid supply step, no liquid is supplied to the surface of the substrate. The substrate processing method of claim 1 or 2, which further includes: an approaching position arranging step, which, in synchronization with the above-mentioned high-conductivity liquid supply step, will have a substrate facing surface facing the entire surface of the substrate The facing member is arranged at a position where the facing surface of the substrate is close to the surface of the substrate. The substrate processing method of claim 1 or 2, further comprising: a second high-conductivity liquid supply step for removing electricity from the substrate after the low-conductivity liquid supply step and before the chemical solution supply step, The highly conductive liquid is supplied to at least the surface of the substrate. The substrate processing method of claim 1 or 2, wherein the substrate holding step includes a step of contacting a conductive portion formed with a conductive material to a peripheral portion of the substrate to thereby hold the substrate. The substrate processing method of claim 1 or 2, wherein the low-conductivity liquid system includes deionized water. The substrate processing method of claim 1 or 2, wherein the high-conductivity liquid system includes a liquid containing ions. A substrate processing apparatus includes: a substrate holding unit that holds a substrate with a pattern formed on the surface; a chemical liquid supply unit for supplying a conductive material to the surface of the substrate held by the substrate holding unit Chemical solution; a low-conductivity liquid supply unit for supplying a low-conductivity liquid with lower conductivity than the aforementioned chemical solution to the surface of the substrate held by the substrate holding unit; a high-conductivity liquid supply unit for To supply a highly conductive liquid with lower conductivity than the chemical solution and higher than the low conductivity liquid to the back surface of the substrate held by the substrate holding unit on the opposite side to the surface; and a control device, which controls The chemical liquid supply unit, the low-conductivity liquid supply unit, and the high-conductivity liquid supply unit; and the control device executes the following steps: a chemical liquid supply step, which supplies the chemical liquid to at least the surface of the substrate; The low-conductivity liquid supply step is described above Before the chemical liquid supply step, in order to remove the charge accumulated on the outer surface of the pattern formed on the surface of the substrate, the low-conductivity liquid is supplied to the surface of the substrate; and the high-conductivity liquid supply step is described above Before the low-conductivity liquid supply step, in order to reduce the charge accumulated in the pattern formed on the above-mentioned surface of the substrate and to pull out the electric charge entering the inside of the pattern to the outer surface of the above-mentioned pattern, the high-conductivity liquid The supply to the substrate is not the above surface of the substrate, but the back surface on the opposite side to the above surface. A substrate processing apparatus according to claim 9, which further includes: an opposing member having a substrate opposing surface that opposes the entire surface of the substrate held by the substrate holding unit, and is disposed on the substrate pair Approach the surface to the proximity position of the above-mentioned surface of the substrate. The substrate processing apparatus according to claim 9 or 10, wherein the substrate holding unit has a conductive pin, and the conductive pin is a holding pin that contacts a peripheral portion of the support substrate and is formed of a conductive material.

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