JP7281868B2 - Substrate processing method and substrate processing apparatus - Google Patents

Description

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

In the manufacturing process of a semiconductor device, for example, a single substrate processing apparatus that processes substrates one by one includes a processing chamber and a spin chuck that rotates the substrate while holding the substrate substantially horizontally in the processing chamber. and a nozzle for ejecting a chemical solution toward the surface of the substrate (the surface on which a pattern (device) is formed) rotated by the spin chuck.

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

A substrate carried into a processing chamber may have charges accumulated (that is, electrified) on its surface due to previous processes (ion implantation, dry etching). If electric charges are accumulated on the surface of the substrate carried into the processing chamber, when the chemical liquid from the nozzle lands on the surface of the substrate, the surface of the substrate and the chemical liquid come into contact with each other, causing abrupt damage on the surface of the substrate. A change in electric charge may occur, and electrostatic discharge (arcing) may occur at or near the position where the chemical solution lands. As a result, local defects may occur on the surface of the substrate, such as destruction of patterns (devices) and holes in patterns.

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 static elimination liquid (for example, carbonated water) having a lower conductivity than the chemical solution is applied to the substrate. It is known to supply to surfaces.

JP 2009-200365 A

However, there are cases where the amount of charge on the substrate carried into the processing chamber is large. Since charge transfer is fast in neutralization using carbonated water, electrostatic discharge may occur due to the contact between the surface of the substrate and the carbonated water when the carbonated water is deposited on the substrate.
Further, in order to gradually reduce the charge amount of the substrate, a static elimination liquid (for example, DIW (deionized water)) having a lower conductivity than carbonated water is supplied to the surface of the substrate, and after the supply, the carbonated water is applied to the surface of the substrate. It is also possible to supply However, if the substrate is highly charged, the supply of DIW to the surface of the substrate may also cause electrostatic discharge.

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 static elimination liquid (carbonated water or DIW) to the substrate. In other words, it is necessary to suppress or prevent the occurrence of electrostatic discharge that accompanies the supply of liquid to the substrate.
SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a substrate processing method capable of suppressing or preventing the occurrence of electrostatic discharge accompanying the supply of liquid to the surface of a substrate, thereby suppressing or preventing the occurrence of local defects on the surface of the substrate. and to provide a substrate processing apparatus.

One embodiment of the present invention is a method for 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 of holding the substrate; and a low-conductivity liquid supply step of supplying a low-conductivity liquid having conductivity lower than that of the chemical solution to the surface of the substrate in order to neutralize the substrate prior to the chemical solution supply step. , prior to the step of supplying the low-conductivity liquid, a high-conductivity liquid having a lower conductivity than the chemical liquid and a higher conductivity than the low-conductivity liquid is applied to the substrate, not the surface of the substrate, in order to neutralize the charge on the substrate; and a step of supplying a highly conductive liquid to the back surface opposite to the front surface.

According to this method, prior to supplying the chemical solution to the substrate, first, the highly conductive liquid is supplied not to the front surface of the substrate but to the back surface of the substrate. If the substrate is charged, the surface of the substrate (the device surface on which the device is formed) is charged, so even if a highly conductive liquid is supplied to the back surface of the substrate, electrostatic discharge will Rarely occurs. Also, 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 surface of the substrate.

In addition, by supplying the highly conductive liquid to the back surface of the substrate, the electric charges that have entered the inside of the pattern on the surface of the substrate can be pulled out to the outer surface of the pattern.
A low-conductivity liquid is then applied to the surface of the substrate. As a result, the charge released 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 is reduced from the substrate, the occurrence of electrostatic discharge can be effectively suppressed or prevented. Moreover, since the conductive liquid is a low-conductive liquid with relatively low conductivity, it is possible to more effectively suppress or prevent the occurrence of electrostatic discharge.

Then, the chemical liquid is supplied to at least the surface of the substrate after the charges are sufficiently removed by the low-conductivity liquid and the high-conductivity liquid. Thus, chemical liquid processing is executed. Therefore, it is possible to suppress or prevent the occurrence of electrostatic discharge accompanying the supply of the chemical solution to the surface of the substrate.
As a result, it is possible to suppress or prevent the occurrence of electrostatic discharge that accompanies the supply of liquid (low-conductivity liquid, high-conductivity liquid, chemical liquid) to the surface of the substrate, thus suppressing the occurrence of local defects on the surface of the substrate. or can be prevented.

The step of applying the low-conductivity liquid includes applying the low-conductivity liquid to the patterned surface of the substrate to remove charge accumulated on the outer surface of the pattern. good too. applying the highly conductive liquid to the back surface of the substrate opposite to the patterned surface to reduce charge build-up on the pattern; may contain
The low-conductivity liquid supply step opens a low-conductivity liquid valve to supply a low-conductivity liquid having a lower conductivity than the chemical liquid from a low-conductivity liquid supply source to the low-conductivity liquid nozzle, The step of supplying the low-conductivity liquid from the low-conductivity liquid nozzle to the patterned surface of the substrate may be included.
The high-conductivity liquid supply step opens a high-conductivity liquid valve different from the low-conductivity liquid valve to supply a high-conductivity liquid supply from a high-conductivity liquid supply different from the low-conductivity liquid supply to the high-conductivity liquid nozzle. Accordingly, the step of supplying the highly conductive liquid from the highly conductive liquid nozzle to the back surface of the substrate may be included.
In one embodiment of the present invention, the substrate processing method includes applying 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. Further comprising the step of providing.
According to this method, the low-conductivity liquid or the 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 charges accumulated in the substrate. Therefore, it is possible to more effectively suppress or prevent the occurrence of electrostatic discharge during supply of the chemical solution.

In one embodiment of the invention, no liquid is supplied to the surface of the substrate concurrently with the highly conductive liquid supply step.
If the liquid is supplied to the front surface of the substrate in parallel with the supply of the highly conductive liquid to the rear surface of the substrate, there is a risk that electrostatic discharge will occur on the front surface of the substrate due to the liquid landing on the front surface of the substrate.
In contrast, according to this method, the liquid is not supplied to the front surface of the substrate in parallel with the supply of the highly conductive liquid to the back surface of the substrate. This makes it 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 substrate processing method includes providing a facing member having a substrate facing surface facing the entire surface of the substrate in parallel with the highly conductive liquid supply step. a proximate position such that the is proximate to the surface of the substrate .
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 surface of the substrate, that is, while protecting the substrate surface by the substrate-facing surface of the opposing member. Therefore, it is possible to satisfactorily suppress or prevent the highly conductive liquid from flowing from the back surface of the substrate to the front surface side of the substrate and the highly conductive liquid from flowing to the front surface side of the substrate.

In one embodiment of the present invention, the substrate processing method includes, after the low-conductivity liquid supply step and prior to the chemical liquid supply step, the high-conductivity liquid on at least the surface of the substrate in order to destaticize the substrate. It further includes a second highly conductive liquid supply step for supplying a conductive liquid.
According to this method, the high-conductivity liquid is supplied to at least the surface of the substrate after the low-conductivity liquid is supplied to the substrate and before the chemical liquid is supplied to the substrate. That is, the surface of the substrate is supplied in the order of low-conductivity liquid to high-conductivity liquid. Electrostatic discharge occurs due to low-conductivity liquid and high-conductivity liquid because the conductive liquid is supplied step by step in order from low-conductivity liquid to high-conductivity liquid to chemical liquid. It is possible to satisfactorily remove static electricity from the substrate while preventing this, and to effectively suppress the occurrence of electrostatic discharge during supply of the chemical solution.

In one embodiment of the present invention, the substrate holding step includes holding the substrate by bringing a conductive portion formed using a conductive material into contact with the peripheral portion of the substrate.
According to this method, the substrate can be satisfactorily neutralized through the low-conductivity liquid or the high-conductivity liquid.

The low-conductivity liquid may comprise deionized water . The highly conductive liquid may include a liquid containing ions.
An embodiment of the present invention comprises a substrate holding unit holding a substrate having a pattern formed on its surface, and a chemical liquid having conductivity for supplying the surface of the substrate held by the substrate holding unit. a chemical solution supply unit; a low-conductivity liquid supply unit for supplying a low-conductivity liquid having conductivity lower than that of the chemical solution to the surface of the substrate held by the substrate holding unit; and the substrate holding unit. A high-conductivity liquid supply unit for supplying a high-conductivity liquid having a lower conductivity than the chemical liquid and a higher conductivity than the low-conductivity liquid to the back surface opposite to the front surface of the substrate held by and a control device for controlling the chemical supply unit, the low-conductivity liquid supply unit, and the high-conductivity liquid supply unit. Then , the control device supplies the chemical solution to the surface of the substrate, and supplies the low-conductivity liquid to the surface of the substrate to neutralize the substrate prior to the chemical solution supply step. and a low-conductivity liquid supply step, prior to the low-conductivity liquid supply step, supplying the high-conductivity liquid not to the front surface of the substrate but to the back surface of the substrate opposite to the front surface. and a liquid supply step .

According to this configuration, prior to supplying the chemical solution to the substrate, the highly conductive liquid is first supplied to the back surface of the substrate instead of the front surface of the substrate. If the substrate is charged, the surface of the substrate (the device surface on which the device is formed) is charged, so even if a highly conductive liquid is supplied to the back surface of the substrate, electrostatic discharge will Rarely occurs. Also, 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 surface of the substrate.

In addition, by supplying the highly conductive liquid to the back surface of the substrate, the electric charges that have entered the inside of the pattern on the surface of the substrate can be pulled out to the outer surface of the pattern.
A low-conductivity liquid is then applied to the surface of the substrate. As a result, the charge released 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 is reduced from the substrate, the occurrence of electrostatic discharge can be effectively suppressed or prevented. Moreover, since the conductive liquid is a low-conductive liquid with relatively low conductivity, it is possible to more effectively suppress or prevent the occurrence of electrostatic discharge.

Then, the chemical liquid is supplied to at least the surface of the substrate after the charges are sufficiently removed by the low-conductivity liquid and the high-conductivity liquid. Thus, chemical liquid processing is executed. Therefore, it is possible to suppress or prevent the occurrence of electrostatic discharge accompanying the supply of the chemical solution to the surface of the substrate.
As a result, it is possible to suppress or prevent the occurrence of electrostatic discharge that accompanies the supply of liquid (low-conductivity liquid, high-conductivity liquid, chemical liquid) to the surface of the substrate, thus suppressing the occurrence of local defects on the surface of the substrate. or can be prevented.

a low-conductivity liquid nozzle for the low-conductivity liquid supply unit to supply a low-conductivity liquid having a lower conductivity than the chemical solution 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 a low-conductivity liquid nozzle, and supplying and stopping the supply of the low-conductivity liquid from the low-conductivity liquid supply source to the low-conductivity liquid nozzle. and a low-conductivity liquid valve for switching between and.
The high-conductivity liquid supply unit has a high-conductivity liquid having a lower conductivity than the chemical liquid and a higher conductivity than the low-conductivity liquid on the back surface opposite to the front surface of the substrate held by the substrate holding unit. a highly conductive liquid nozzle for supplying a conductive liquid ; and a highly conductive liquid supply source different from the low conductive liquid supply for supplying the highly conductive liquid to the highly conductive liquid nozzle; A high-conductivity liquid valve for switching between supplying and stopping the supply of the high-conductivity liquid from the high-conductivity liquid supply source to the high-conductivity liquid nozzle, the high-conductivity liquid being different from the low-conductivity liquid valve. A valve may also be included.
The controller may control the low-conductivity liquid valve and the high-conductivity liquid valve.
The low-conductivity liquid supply step opens the low-conductivity liquid valve to remove the charge accumulated on the outer surface of the pattern, and the low-conductivity liquid is applied to the patterned surface of the substrate. supplying the low-conductivity liquid through a conductive liquid nozzle. The highly conductive liquid supplying step opens the highly conductive liquid valve and dispenses the highly conductive liquid through the highly conductive liquid nozzle to the substrate to reduce the charge accumulating on the pattern. The step of providing the back surface opposite to the patterned surface may be included.
In one embodiment of the present invention, the substrate processing apparatus has a substrate facing surface that faces 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 arranged in such a proximate position.
According to this configuration, the highly conductive liquid can be supplied to the back surface of the substrate while bringing the substrate-facing surface of the opposing member close to the surface of the substrate, that is, while protecting the substrate surface by the substrate-facing surface of the opposing member. It is possible. In this case, it is possible to satisfactorily suppress or prevent the highly conductive liquid from flowing from the back surface of the substrate to the front side of the substrate, or from flowing to the front side of the substrate.

In one embodiment of the present invention, the substrate holding unit has a holding pin that contacts and supports the peripheral edge of the substrate and is formed using a conductive material .
According to this configuration, the substrate can be satisfactorily destaticized via the low-conductivity liquid or the high-conductivity liquid.

FIG. 1 is an illustrative plan view for explaining the internal layout of a substrate processing apparatus according to one embodiment of the present invention. FIG. 2 is an illustrative cross-sectional view for explaining a configuration example of a processing unit provided in the substrate processing apparatus. FIG. 3A is a block diagram for explaining the electrical configuration of the main parts of the substrate processing apparatus. FIG. 3B is an enlarged view of the surface Wa of the substrate W to be processed by the substrate processing apparatus. It is a cross-sectional view shown in FIG. FIG. 4 is a flowchart for explaining a first example of substrate processing by the processing unit. 5A to 5C are schematic diagrams of the substrate viewed horizontally during each step of the first substrate processing example. 6A to 6C are diagrams for explaining changes in the charged state of the substrate in each step of the first substrate processing example. 7A to 7C are diagrams for explaining the details of the chemical supply process included in the first substrate processing example. FIG. 8 is a diagram showing test results of the static elimination test. FIG. 9 is a flowchart for explaining a second example of substrate processing performed by the processing unit. FIG. 10 is a flowchart for explaining a third example of substrate processing performed by the processing unit.

BEST MODE FOR CARRYING OUT THE INVENTION Below, embodiments of the present invention will be described in detail with reference to the accompanying drawings.
FIG. 1 is a schematic top view of a substrate processing apparatus 1 according to an embodiment of the present invention. 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 load port LP on which a substrate container housing a plurality of substrates W to be processed by the processing units 2 is placed. , an indexer robot IR and a substrate transport robot CR that transport substrates W between the load port LP and the processing unit 2 , and a controller 3 that controls the substrate processing apparatus 1 . The indexer robot IR transports substrates W between the substrate container and the substrate transport robot CR. The substrate transport robot CR transports substrates W between the indexer robot IR and the processing units 2 . A plurality of processing units 2 have, for example, the same configuration.

FIG. 2 is an illustrative cross-sectional view for explaining a configuration example of the processing unit 2. As shown in FIG.
The processing unit 2 holds a box-shaped processing chamber 4 and one substrate W in the processing chamber 4 in a horizontal posture, and rotates the substrate W around a vertical rotation axis A1 passing through the center of the substrate W. A spin chuck (substrate holding unit) 5 and a liquid (processing liquid (chemical and rinsing liquid) are applied to the upper surface of the substrate W held by the spin chuck 5 (the surface (pattern formation surface) Wa of the substrate W (see FIG. 5A, etc.)). liquid) and static elimination liquid), and the liquid (processing liquid (chemical liquid and a lower liquid supply unit for supplying a rinse liquid) and a static elimination liquid), and the upper surface of the substrate W held by the spin chuck 5, and shield the space above the substrate W from the surrounding atmosphere. It includes a facing member 6 and a cylindrical processing cup (not shown) surrounding the sides of the spin chuck 5 .

The processing chamber 4 includes a box-shaped partition 7 that accommodates the spin chuck 5 and the like.
As the spin chuck 5, a clamping type chuck that holds the substrate W horizontally by sandwiching the substrate W in the horizontal direction is employed. Specifically, the spin chuck 5 includes a spin motor (rotation unit) 12, a lower spin shaft 13 integrated with the drive shaft of the spin motor 12, and an upper end of the lower spin shaft 13 attached substantially horizontally. A disk-shaped spin base 14 is included. Lower spin shaft 13 is formed using a conductive material. The lower spin shaft 13 is grounded.

The spin base 14 includes a horizontal circular upper surface 14a having an outer diameter greater than the outer diameter of the substrate W. As shown in FIG. The spin base 14 is formed using a conductive material. A plurality of (three or more, for example, six) clamping pins 15 are arranged on the periphery of the upper surface 14a. A plurality of clamping pins 15 are arranged at appropriate intervals, for example, at equal intervals on a circumference corresponding to the outer peripheral shape of the substrate W, on the peripheral edge of the upper surface of the spin base 14 . The holding pins 15 are so-called conductive pins made of a conductive material.

As described above, the lower spin shaft 13, the spin base 14, and the clamping pins 15 are each formed using a conductive material (eg, a conductive material containing carbon, a metal material), and the lower spin shaft 13 is grounded. Therefore, when a liquid having conductivity (a low-conductivity liquid, a high-conductivity liquid, and a chemical liquid, which will be described later) is supplied to the front surface or the rear surface of the substrate W held by the spin chuck 5, the substrate W is exposed to the liquid through the liquid. is neutralized.

The facing member 6 includes a facing plate 17 and a top surface nozzle (low-conductivity liquid nozzle) 30 penetrating vertically through the central portion of the facing plate 17 . The opposing plate 17 has a horizontally disposed circular substrate opposing surface 17a that faces the entire upper surface of the substrate W on its lower surface.
In this embodiment, top surface nozzle 30 functions as a central axis nozzle. The top nozzle 30 is arranged above the spin chuck 5 . Top nozzle 30 is supported by support arm 22 . Top nozzle 30 is non-rotatable with respect to support arm 22 . The upper nozzle 30 moves up and down together with the opposing plate 17 and the support arm 22 . The top surface nozzle 30 has a discharge port 30 a formed at its lower end facing the center of the top surface of the substrate W held by the spin chuck 5 .

The supporting arm 22 is coupled with an opposing member elevating unit 27 including an electric motor, a ball screw, and the like. 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 facing member elevating unit 27 moves the facing plate 17 to a close position (a position indicated by a two-dot chain line in FIG. 2) where the substrate facing surface 17a is close to the upper surface of the substrate W held by the spin chuck 5. Also shown in FIG. 5A. ) and the retracted position (the position indicated by the solid line in FIG. 2), which is retracted to a greater extent than the approach position. The opposing member elevating unit 27 can hold the opposing plate 17 at a close position (position shown in FIG. 5A), an upper position (positions shown in FIGS. 5B and 5C), and a retracted position. The close position is a position where the substrate facing surface 17a is arranged with a small gap (for example, about 0.3 mm) from the upper surface of the substrate W. FIG. The upper position is a position where the space 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 a top nozzle 30, and a first top supply unit 31, a second top supply unit 32 and a third top supply unit 33 that supply processing liquids to the top nozzle 30, respectively.
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 connection portion 36 for sending liquid to the upper common pipe 35 and a plurality of valves. Inside the upper connection portion 36, a circulation space is formed for the liquid to circulate. The upper mixing valve unit UMV further includes an upper DIW pipe 37 , an upper SC2 pipe 38 and an upper suction pipe 39 respectively connected to the upper connection 36 . The plurality of valves included in the upper mixing valve unit UMV are an upper DIW valve (low-conductivity liquid valve) 42 that opens and closes the upper DIW pipe 37 , an upper SC2 valve 43 that opens and closes the upper SC2 pipe 38 , and an upper suction pipe 39 . and an upper suction valve 44 that opens and closes the .

The DIW upper pipe 37 is supplied with DIW (deionized water) from a DIW supply source (low-conductivity liquid supply source) . When the DIW upper valve is opened while the other valves included in the upper liquid supply unit are closed, DIW is supplied to the upper nozzle 30, whereby DIW is ejected downward from the ejection port 30a.
SC2 (mixed solution containing HCl and H ₂ O ₂ ) from an SC2 supply source is supplied 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 surface 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. Ejector-type suction devices include a vacuum generator and an aspirator. In the operating state of the suction device, the inside of the suction device is depressurized, so that the inside of the upper suction pipe 39 is sucked, and as a result, the function of the suction device is activated. When the function of the suction device is activated, the upper suction valve 44 is opened while the other valves included in the upper liquid supply unit are closed. The liquid in the internal 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 (mixed liquid containing NH ₄ OH and H ₂ O ₂ ) from an SC1 supply source is supplied 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, the SC1 is supplied to the upper surface nozzle 30, whereby the SC1 is ejected downward from the ejection port 30a.

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

In this embodiment, the upper nozzle 30, the DIW upper pipe 37 and the DIW upper valve 42 constitute a low-conductivity liquid supply unit.
The lower liquid supply unit includes a lower surface nozzle (highly conductive liquid nozzle) 50, and a first lower supply unit 51, a second lower supply unit 52 and a third lower supply unit that supply processing liquid to the lower surface nozzle 50, respectively. and unit 53 .

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 portion 56 for sending liquid to the lower common pipe 55 and a plurality of valves. A circulation space is formed inside the lower connection portion 56 for the circulation of the liquid. The lower mixing valve unit DMV further includes a DIW lower line 57, a SC2 lower line 58, a _CO2 water lower line 60 and a lower suction line 59 connected to the lower connection 56 respectively. The plurality of valves included in the lower liquid supply unit are a DIW lower valve 62 that opens and closes the DIW lower line 57 , an SC2 lower valve 63 that opens and closes the _SC2 lower line 58 , and a CO ₂ It includes a water bottom valve (highly conductive liquid valve) 65 and a bottom suction valve 64 that opens and closes the bottom suction line 59 .

The DIW lower pipe 57 is supplied with DIW from a DIW supply source. By opening the DIW lower valve 62 while the other valves included in the lower mixing valve unit DMV are closed, DIW is supplied to the lower surface nozzle 50, whereby DIW is ejected upward from the ejection port 50a.
The SC2 lower pipe 58 is supplied with SC2 from an SC2 supply source. When the SC2 lower valve 63 is opened while the other valves included in the lower liquid supply unit are closed, SC2 is supplied to the lower surface nozzle 50, whereby SC2 is ejected upward from the ejection port 50a.

The _CO2 water pipe 60 is adapted to be supplied with _CO2 water from a _CO2 water supply source (highly conductive liquid supply source) . CO2 water is supplied to the lower surface nozzle 50 by opening the _CO2 water valve 65 while other valves included in the lower liquid supply unit are closed, whereby _{the CO2} water is supplied from the discharge port 50a. It is ejected upward.
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. Ejector-type suction devices include a vacuum generator and an aspirator. In the operating state of the suction device, the inside of the suction device is depressurized, so that the inside of the lower suction pipe 59 is sucked, and as a result, the action of the suction device is enabled. When the function of the suction device is activated, the lower suction valve 64 is opened while the other valves included in the lower liquid supply unit are closed, thereby sucking the inside of the lower suction pipe 59 and connecting the lower connection. The liquid in the internal space (circulation space) of the portion 56 and the liquid inside 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 surface nozzle 50 and an SC1 lower valve 67 interposed in the SC1 lower pipe 66 . The SC1 lower pipe 66 is supplied with SC1 from an SC1 supply source. When the SC1 lower valve 67 is opened while the other valves included in the lower liquid supply unit are closed, SC1 is supplied to the lower surface nozzle 50, whereby SC1 is ejected upward from the ejection port 50a.

The third lower supply unit 53 includes a lower HF pipe 68 connected to the lower nozzle 50 and a lower HF valve 69 interposed in the lower HF pipe 68 . HF from an HF supply source is supplied to the lower HF 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 surface nozzle 50, whereby HF is ejected upward from the ejection port 50a. In this embodiment, the HF is, for example, dilute dilute hydrofluoric acid (DHF).

In this embodiment, the bottom surface nozzle 50, the _CO2 submerged pipe 60 and the _CO2 submerged valve 65 constitute a highly conductive liquid supply unit.
FIG. 3A is a block diagram for explaining the electrical configuration of the main part of the substrate processing apparatus 1. As shown in FIG.
The control device 3 is configured using, for example, a microcomputer. The control device 3 has an arithmetic unit such as a CPU, a fixed memory device, a storage unit such as a hard disk drive, and an input/output unit. The storage unit stores a program executed by the arithmetic unit.

The control device 3 is also connected to the spin motor 12, the opposing member lifting unit 27, and the like as objects to be controlled. The control device 3 controls the operations of the spin motor 12, the opposing member elevating unit 27, etc. according to a predetermined program.
In addition, the control device 3 controls 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, the DIW lower valve 62, the SC2 lower valve 63, the lower Open and close suction valve 64, _CO2 water bottom valve 65, SC1 bottom valve 67, HF bottom valve 69.

A case of processing a substrate W having a pattern 100 formed on its front surface (front surface) Wa, which is a pattern formation surface (device formation surface), will be described below.
FIG. 3B is a cross-sectional view showing an enlarged front surface Wa of the substrate W to be processed by the substrate processing apparatus 1. As shown in FIG. A substrate W to be processed is, for example, a silicon wafer, and a pattern 100 is formed on its surface Wa, which is a pattern forming surface. Pattern 100 is, for example, a fine pattern. The pattern 100 may be formed by arranging structures 101 having a convex shape (columnar shape) in a matrix, as shown in FIG. 3B. In this case, the line width W1 of the structure 101 is, for example, approximately 3 nm to 45 nm, and the gap W2 of the pattern 100 is, for example, approximately 10 nm to several μm. The film thickness T of the pattern 100 is, for example, approximately 0.2 μm to 1.0 μm. Also, the pattern 100 may have an aspect ratio (ratio of film thickness T to line width W1) of, for example, about 5 to 500 (typically about 5 to 50).

Further, the pattern 100 may be a line-shaped pattern formed by fine trenches arranged repeatedly. Alternatively, the pattern 100 may be formed by providing a thin film with a plurality of fine holes (voids or pores).
Pattern 100 includes, for example, an insulating film. Moreover, the pattern 100 may include 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 ( _SiO2 film) or a silicon nitride film (SiN film). Also, the conductor film may be an amorphous silicon film into which impurities are introduced to reduce the resistance, or may be a metal film (for example, a TiN film).

Also, the pattern 100 may be a hydrophilic film. A TEOS film (a kind of silicon oxide film) can be exemplified as a hydrophilic film.
FIG. 4 is a flowchart for explaining the details of the first example of substrate processing executed in the processing unit 2. As shown in FIG. 5A to 5C are schematic diagrams of the substrate viewed horizontally during each step of the first substrate processing example. 6A to 6C are diagrams for explaining changes in the charged state of the substrate W in each step of the first substrate processing example.

A first substrate processing example will be described with reference to FIGS. 5A-7C will be discussed as appropriate. A first substrate processing example is a cleaning process for removing foreign substances (particles) from the surface of the substrate W. FIG. A second substrate processing example and a third substrate processing example, which will be described later, are similarly cleaning processes for removing foreign matter from the surface of the substrate W. FIG.
An unprocessed substrate W (for example, a circular substrate with a diameter of 300 mm) is loaded from the substrate container C into the processing unit 2 by the indexer robot IR and the substrate transport robot CR and loaded into the processing chamber 4, where the substrate W is placed on its surface Wa. (pattern formation surface; device formation surface; see FIG. 3B, etc.) is transferred to the spin chuck 5, and the substrate W is held by the spin chuck 5 (substrate holding step; S1 in FIG. 4: substrate). W loading). In this state, the back surface Wb (see FIG. 6A, etc.) of the substrate W faces downward.

The substrate W carried into the inner space of the processing chamber 4 may have charges accumulated (that is, charged) due to the previous processes (ion implantation, dry etching). When the substrate W is charged, the charge is primarily accumulated on the surface Wa of the substrate W, as shown in FIG. 6A. More specifically, the charges are trapped inside the pattern 100 on the surface Wa of the substrate W. As shown in FIG. When a chemical solution (a conductive chemical solution such as SC1 or SC2) is supplied to the substrate W, the surface Wa of the substrate W and the chemical solution come into contact with each other, causing a sudden charge change on the surface Wa of the substrate W and causing the chemical solution to adhere. Electrostatic discharge may occur at or near the liquid level. As a result, local defects may occur on the surface Wa of the substrate W, such as destruction of the pattern 100 and formation of holes in the pattern 100 . Therefore, prior to the chemical solution supply step S5, the high-conductivity liquid supply step S3 and the low-conductivity liquid supply step S4 are performed to neutralize the substrate W. FIG.

After the substrate transport robot CR withdraws from the processing unit 2, the control device 3 controls the spin motor 12 to increase the rotation speed of the spin base 14 to a predetermined static elimination rotation speed (less than about 500 rpm, for example about 200 rpm). The static elimination rotation speed is maintained (S2 in FIG. 4: substrate W rotation start).
In addition, the control device 3 controls the opposing member elevating unit 27 to lower the opposing plate 17 from the retracted position and arrange it 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, as shown in _FIG . is supplied not to the front surface Wa of the substrate W but to the rear surface Wb of the substrate W (S3 in FIG. 4). _CO2 water has a somewhat high electrical conductivity due to the ion content. 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. , more specifically from about 20 MΩ-cm to about 30 MΩ-cm.

Specifically, the controller 3 opens the CO ₂ submerged valve 65 . As a result, the CO ₂ water is discharged from the discharge port 50a of the lower surface nozzle 50 toward the central portion of the back surface Wb (that is, the lower surface) of the substrate W in the rotating state. The CO ₂ water that has landed on the rear surface Wb of the substrate W moves to the peripheral portion of the substrate W due to the centrifugal force caused by the rotation of the substrate W. As shown in FIG. As a result, a liquid film of CO ₂ water covering the entire rear surface Wb of the substrate W is formed.

Since the conductivity of _CO2 water is relatively high, the supply of _CO2 water as a highly conductive liquid to the back surface Wb of the substrate W effectively reduces the amount of charge accumulated in the pattern 100 of the substrate W. can be made Further, by supplying the CO ₂ water to the back surface Wb of the substrate W, the charges that have entered the pattern 100 on the front surface Wa of the substrate W can be pulled out to the outer surface of the pattern 100 as shown in FIG. 6B. 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 front surface Wa of the substrate W can be diffused. Since charges are accumulated on the front surface Wa (pattern 100) of the substrate W, electrostatic discharge hardly occurs on the rear surface Wb of the substrate W even if the _CO2 water is supplied to the rear surface Wb of the substrate W.

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 the _CO2 water to the back surface Wb of the substrate W, the liquid lands on the surface Wa of the substrate W, Electrostatic discharge may occur on the surface Wa of the substrate W. As shown in FIG.
In the highly conductive liquid supply step S3, since the liquid is not supplied to the front surface Wa of the substrate W in parallel with the supply of the _CO2 water to the back surface Wb of the substrate W, the generation of electrostatic discharge on the front surface Wa of the substrate W can be prevented more effectively. Can be effectively suppressed or prevented.

In addition, in the highly conductive liquid supply step S3, while the facing member 6 is arranged at a close position, that is, while the front surface Wa of the substrate W is protected by the substrate facing surface 17a of the facing member 6, CO is applied to the back surface Wb of the substrate W. ₂ Supply water. Therefore, the intrusion of CO ₂ water from the rear surface Wb of the substrate W to the front surface Wa side of the substrate W can be suppressed or prevented satisfactorily.
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 in the inert gas pipe. In this case, the inert gas pipe is supplied with an inert gas (for example, _N2 gas, helium gas, argon gas, or mixed gas thereof) from an inert gas supply source. The inert gas valve is controlled by controller 3 . In this case, in the highly conductive liquid supply step S3, the control device 3 opens the inert gas valve with the opposing member 6 arranged at the close position, thereby supplying the inert gas to the upper surface nozzle 30 through the inert gas pipe. is supplied, 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 shown in FIG. As a result, a stream of 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 intrusion of CO ₂ water from the rear surface Wb of the substrate W to the front surface Wa side of the substrate W can be suppressed or prevented more satisfactorily.

After a predetermined first static elimination period (for example, about 60 seconds) has elapsed since the start of the _CO2 water discharge, the control device 3 closes the _CO2 underwater valve 65 to stop discharging the _CO2 water from the lower surface nozzle 50. do. This completes the highly conductive liquid supply step S3.
After completion of the highly conductive liquid supply step S3, the control device 3 opens the lower suction valve 64. As shown in FIG. As a result, the CO ₂ water is removed by suction 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 controller 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 close position to the upper position as shown in FIG. 5B.
Next, as shown in FIG. 5B, the control device 3 applies low-conductivity liquids (chemicals (eg, SC1, SC2) and high-conductivity liquids (eg, _CO2 water) to the front surface Wa of the substrate W and the back surface Wb of the substrate W). A low-conductivity liquid supply step (S4 in FIG. 4) is performed to supply DIW as a liquid having a conductivity lower than that of the DIW. Since DIW contains few ions, its conductivity is rather 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 controller 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 (that is, the upper surface) of the substrate W in the rotating state. The DIW that has landed on the surface Wa of the substrate W receives centrifugal force due to the rotation of the substrate W and moves to the peripheral portion of the substrate W. As shown in FIG. As a result, a DIW liquid film covering the entire surface Wa of the substrate W is formed. At the same time, 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 back surface Wb (that is, the lower surface) of the substrate W in the rotating state. As a result, a DIW liquid film covering the entire rear surface Wb of the substrate W is formed.

By supplying _CO2 water to the back surface Wb of the substrate W, as shown in FIG. 6C, the charge drawn to the outer surface of the pattern 100 is effectively removed by supplying DIW to the front 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, which has relatively low conductivity, the occurrence of electrostatic discharge can be more effectively suppressed or prevented.

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. As shown in FIG. As a result, the charges accumulated on the substrate W can be removed more effectively.
When a predetermined second static elimination period (for example, about 60 seconds) elapses from the start of DIW discharge, the controller closes the DIW upper valve 42 and the DIW lower valve 62 to discharge DIW from the upper surface nozzles 30 and to discharge DIW from the lower surface nozzles. Discharge of DIW from 50 is stopped. This completes the low-conductivity liquid supply step S4.

After completing the low-conductivity liquid supply step S<b>4 , the control device 3 opens the upper suction valve 44 . As a result, the DIW is removed by suction from the interior of the upper common pipe 35 and the interior space of the upper connection portion 36 . After removing the DIW, the controller 3 closes the upper suction valve 44 .
Further, the control device 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, approximately 500 rpm) and maintains the liquid processing rotational speed.

Next, as shown in FIG. 5C, the control device 3 supplies the chemical solution to the surface Wa of the substrate W to perform the chemical solution supply step (S5 in FIG. 4) of processing (cleaning) the surface Wa of the substrate W. In the chemical liquid supply step S5 according to this embodiment, the control device 3 supplies the chemical liquid not only to the front surface Wa of the substrate W but also to the rear surface Wb of the substrate W to process (clean) the rear surface Wb of the substrate W. (simultaneous two-sided processing). In the chemical solution supply step S5, SC1 or SC2 is supplied to the front surface Wa of the substrate W first. SC1 and SC2 have high conductivity due to the large amount of ions they contain. The electrical resistivity of SC1 supplied to the substrate W is, for example, on the order of 10 ⁻³ MΩ·cm. The electric resistivity of SC2 supplied to the substrate W is, for example, approximately 10 ⁻⁵ MΩ·cm.

SC1 and SC2 are liquids with higher electrical conductivity than _CO2 water. Therefore, when SC1 or SC2 is supplied to the surface Wa of the substrate W in a state in which the surface Wa of the substrate W is not sufficiently neutralized (a state in which a large amount of charge is accumulated on the surface Wa of the substrate W), SC1 Alternatively, when the SC2 lands on the surface Wa of the substrate W, the surface Wa of the substrate W and SC1 or SC2 come into contact with each other, causing a sudden charge change on the surface Wa of the substrate W, and the chemical liquid on the surface Wa of the substrate W. Electrostatic discharge may occur at or near the liquid landing position.

However, since SC1 or SC2 is supplied to the surface Wa of the substrate W after the electric charges have been sufficiently removed by DIW and _CO2 water, SC1 or SC2 does not adhere to the surface Wa of the substrate W in the chemical solution supply step S5. Electrostatic discharge does not occur when wet.
After the chemical solution supply step S5 is completed, the control device 3 supplies DIW as a rinse solution to the surface Wa of the substrate W to wash away the chemical solution adhering to the surface Wa of the substrate W (see FIG. 4). S6) is executed. In the rinsing step S6 according to this embodiment, the back surface Wb of the substrate W is processed (cleaned) by supplying DIW as a rinsing liquid not only to the front surface Wa of the substrate W but also to the back surface Wb of the substrate W. (Simultaneous double-sided processing).

DIW is supplied to the front surface Wa and rear surface Wb of the substrate W by opening the DIW upper valve 42 and the DIW lower valve 62 by the controller 3 . After a predetermined period of time has passed since the DIW upper valve 42 and the DIW lower valve 62 were opened, the control device 3 closes the DIW upper valve 42 and the DIW lower valve 62 . As a result, the supply of DIW to the front surface Wa and rear surface Wb of the substrate W is stopped, and the rinsing step S6 is completed. Although DIW was used as the rinse liquid, _CO2 water may be used as the rinse 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 the drying process (S7 in FIG. 4). Specifically, the control device 3 increases the rotation speed of the substrate W to a predetermined shake-off speed (for example, several thousand rpm) higher than the liquid processing rotation speed, and rotates the substrate W at the shake-off speed. 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 shaken off around the substrate W. FIG. In this way, the liquid is removed from the substrate W and the substrate W is dried.

After a predetermined period has elapsed since the drying step S7 was started, the control device 3 controls the spin 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 transport robot CR enters the inner space of the processing chamber 4 and unloads the processed substrate W out of the processing chamber 4 (S9 in FIG. 4). The substrate W is transferred from the substrate transport robot CR to the indexer robot IR, and stored in the substrate container C by the indexer robot IR.

7A to 7C are diagrams for explaining the contents of the chemical supply step S5 included in the first substrate processing example. The chemical solution supply step S5 is a step of cleaning the front surface Wa and the back surface Wb of the substrate W using a chemical solution.
Examples of the chemical solution supply step S5 include 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 solution supply step S51 includes an SC1 supply step of supplying SC1 to the front surface Wa and the rear surface Wb of the substrate W, and after this SC1 supply step, DIW (a rinse solution) is applied to the front surface Wa and the rear surface Wb of the substrate W. or _CO2 water), an SC2 supply step of supplying SC2 to the front surface Wa and the back surface Wb of the substrate W after this intermediate rinse step, and an SC2 supply step of supplying SC2 to the front surface Wa and the back surface Wb of the substrate W after this an intermediate rinsing step of supplying DIW (or _CO2 water) as a rinsing liquid to the substrate W and the back surface Wb; and a supply step.

The second chemical solution supply step S52 includes an SC2 supply step of supplying SC2 to the front surface Wa and the back surface Wb of the substrate W, and after this SC2 supply step, DIW ( or _CO2 water), and an SC1 supply step of supplying SC1 to the front surface Wa and the back surface Wb of the substrate W after the intermediate rinse step.
The third chemical solution supply step S53 includes an SC1 supply step of supplying SC1 to the front surface Wa and the back surface Wb of the substrate W. As shown in FIG.

In addition, the processing liquid (chemical liquid or rinse liquid (in this embodiment, DIW, _CO2 water, SC2)) from the upper nozzle 30 or the lower nozzle 50 using the upper mixing valve unit UMV or the lower mixing valve unit DMV. In the case of supply, the corresponding upper suction valve 44 or lower suction valve 64 is opened after the treatment liquid is discharged from the upper surface nozzle 30 or the lower surface nozzle 50, and the inside of the upper common pipe 35 or the lower common pipe 55, and DIW or CO ₂ water is aspirated from the inner space of the upper connection 36 or the lower connection 56 .

As described above, according to this embodiment, CO ₂ water is first supplied not to the front surface Wa of the substrate W but to the rear surface Wb of the substrate W before the chemical solution (SC1 or SC2) is supplied to the substrate W. When the substrate W is charged, the charge is accumulated on the front surface Wa of the substrate W. Therefore, even if the _CO2 water is supplied to the back surface Wb of the substrate W, electrostatic discharge occurs on the back surface Wb of the substrate W. very few. In addition, since the conductivity of the _CO2 water is relatively high, the amount of charges accumulated on the substrate W can be effectively reduced by supplying the _CO2 water to the back surface Wb of the substrate W. FIG.

In addition, by supplying the CO ₂ water to the back surface Wb of the substrate W, the charges that have entered the inside of the pattern 100 on the front surface Wa of the substrate W can be pulled out to the outer surface of the pattern 100 .
DIW is then applied to the front surface Wa of the substrate W. As shown in FIG. As a result, charges drawn to the outer surface of the pattern 100 can be effectively removed by 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, which has relatively low conductivity, the occurrence of electrostatic discharge can be more effectively suppressed or prevented.

Then, the chemical solution supply step S5 is performed on at least the surface Wa of the substrate W after the charge has been sufficiently removed by DIW and _CO2 water. Therefore, it is possible to suppress or prevent the occurrence of electrostatic discharge accompanying the supply of SC1 and SC2 to the surface Wa of the substrate W in the chemical solution supply step S5.
This can suppress or prevent the occurrence of electrostatic discharge accompanying the supply of the liquid (DIW, _CO2 water, chemical solution) to the surface Wa of the substrate W, and therefore suppress the occurrence of local defects on the surface Wa of the substrate W. or can be prevented.

Next, the static elimination test will be described.
In the static elimination test, the samples were subjected to the substrate treatment method (cleaning treatment) according to the following examples and comparative examples.
Example: A substrate W (semiconductor wafer, outer diameter 300 (mm)) having a pattern 100 (see FIG. 3B) arranged on the surface Wa was adopted as a sample, and a spin chuck 5 (see FIG. 3B) was used with the surface Wa facing upward. 2). Using the processing unit 2, the first substrate processing example (cleaning processing) shown in FIG.

Comparative Examples 1 to 9: A substrate W (semiconductor wafer, outer diameter 300 (mm)) having a pattern 100 (see FIG. 3B) arranged on the surface Wa was adopted as a sample, and a spin chuck was performed with the surface Wa facing upward. 5 (see FIG. 2). A cleaning process was performed using the processing unit 2 on the sample held by the spin chuck 5 and in a rotating state. Comparative Examples 1 to 9 differ from the example shown in FIG. 4 above in the content of the static elimination step (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-conductivity liquid supply step S3 and the step corresponding to the low-conductivity liquid supply step S4 are not performed. That is, the chemical solution supply step S5 is executed first.
Comparative Example 2: Instead of the highly conductive liquid supply step S3, a step of supplying _CO2 water to the front surface Wa of the substrate W instead of the back surface Wb of the substrate W is performed. A step corresponding to the low-conductivity liquid supply step S4 is not performed. That is, after the _CO2 water is supplied to the surface Wa of the substrate W, the chemical solution supply step S5 is performed.

Comparative Example 3: A highly conductive liquid supply step S3 was performed. A step corresponding to the low-conductivity liquid supply step S4 is not performed. That is, the chemical solution supply step S5 is performed after the highly conductive liquid supply step S3.
Comparative Example 4: Instead of the highly conductive liquid supply step S3, a step of supplying _CO2 water not only to the back surface Wb of the substrate W but also to the front surface Wa of the substrate W is performed. A step corresponding to the low-conductivity liquid supply step S4 is not performed. That is, after the _CO2 water is supplied to the surface Wa of the substrate W, the chemical solution supply step S5 is performed.

Comparative Example 5: A step corresponding to the highly conductive liquid supply step S3 was not performed. A step corresponding to the low-conductivity liquid supply step S4 is performed first. In this step, a step of supplying DIW to the front surface Wa of the substrate W, not to the back surface Wb of the substrate W, is performed.
Comparative Example 6: A step corresponding to the highly conductive liquid supply step S3 was not performed. A step corresponding to the low-conductivity liquid supply step S4 is performed first. In this step, a step of supplying DIW to the back surface Wb of the substrate W, not to the front surface Wa of the substrate W, is performed.

Comparative Example 7: A step corresponding to the highly conductive liquid supply step S3 was not performed. A low-conductivity liquid supply step S4 is performed first.
Comparative Example 8: Instead of the highly conductive liquid supply step S3, a step of supplying _CO2 water not only to the back surface Wb of the substrate W but also to the front surface Wa of the substrate W is performed. After this step, a low-conductivity liquid supply step S4 is performed.

Comparative Example 9: Instead of the highly conductive liquid supply step S3, a step of supplying _CO2 water to the front surface Wa of the substrate W instead of the back surface Wb of the substrate W is performed. After this step, a low-conductivity liquid supply step S4 is performed.
The test results are shown in FIG. In the example, no electrostatic discharge occurred. On the other hand, in Comparative Examples 1 to 9, traces of electrostatic discharge were found in the central portion of the surface Wa of the substrate W. FIG. In Comparative Examples 2, 4, 8 and 9, the surface of the substrate W is first supplied with CO ₂ water having high conductivity. It is considered that electrostatic discharge occurred with the supply of this _CO2 water.

In comparative examples 5 and 7, DIW with low conductivity is applied to the surface Wa of the substrate W first. Even with this supply of DIW, the surface Wa of the substrate W (particularly, the charge that has entered the pattern 100 as shown in FIG. 6A) is not sufficiently removed, and therefore the subsequent charge on the surface Wa of the substrate W is It is considered that electrostatic discharge occurred with the supply of the chemical solution.

In Comparative Examples 1, 3 and 6, the chemical solution having high conductivity is supplied to the surface Wa of the substrate W first. It is considered that the front surface Wa of the substrate W was not sufficiently destaticized before the supply of the chemical solution was started, and therefore the electrostatic discharge was generated along with the supply of the chemical solution to the surface Wa of the substrate W.
Although one embodiment of the present invention has been described above, 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. As shown in FIG. The second substrate processing example shown in FIG. 9 differs from the first substrate processing example shown in FIG. The point is that the liquid supply step S11 is adopted. In the low-conductivity liquid supply step S11, DIW is supplied only to the front surface Wa of the substrate W, not to both the front surface Wa and the rear surface Wb of the substrate W. As shown in FIG.

In addition, in the first substrate processing example shown in FIG. 4, in the low-conductivity liquid supply step S4, DIW as a low-conductivity liquid is supplied to the front surface Wa of the substrate W, while the back surface Wb of the substrate W is supplied with a high-conductivity liquid. You may make it supply _CO2 water as a liquid.
FIG. 10 is a flowchart for explaining a third example of substrate processing performed by the processing unit 2. As shown in FIG.

The third example of substrate processing shown in FIG. 10 differs from the first example of substrate processing shown in FIG. In order to achieve this, at least the surface Wa (both the surface Wa and the back surface Wb (or only the surface Wa)) of the substrate W is coated with CO as a highly conductive liquid (a liquid having a lower conductivity than the chemical liquids (eg SC1, SC2)). _2. The point is that the second highly conductive liquid supply step S21 for supplying water is executed.

As indicated by the dashed line in FIG. 2, the upper mixing valve unit UMV further includes a _CO2 water pipe 40 connected to the upper connection 36 and a _CO2 water valve 45 for opening and closing the _CO2 water pipe 40. good too. CO2 water is supplied to the upper surface nozzle 30 by opening the _CO2 water valve 45 while other valves included in the upper liquid supply unit are closed, thereby causing _{the CO2} water to flow downward from the discharge port 30a. Dispensed.

According to this third substrate processing example, _CO2 water is supplied to at least the surface Wa of the substrate W after the DIW is supplied to the substrate W and before the substrate W is supplied with the chemical solution. That is, DIW→CO ₂ water is supplied to the surface Wa of the substrate W in this order. Since the conductive liquid is supplied to the substrate step by step in the order of DIW → _CO2 water → chemical liquid in order from the one with the lowest conductivity, the substrate W is prevented from generating electrostatic discharge due to DIW and _CO2 water. can be satisfactorily eliminated, thereby effectively suppressing the occurrence of electrostatic discharge during the supply of the chemical solution.

In addition, as the chemical solution supply step S5, both surfaces (the front surface Wa and the back surface Wb) of the substrate W are treated with the chemical solution as an example. The back surface Wb) may be treated with a chemical solution.
Further, SC1 and SC2 were exemplified as the chemical solutions initially supplied to the surface Wa of the substrate W in the chemical solution supply step S5, but other chemical solutions (ozone water and SPM (including H ₂ SO ₄ and H ₂ O ₂₎ may be used. mixture), HF, etc.).

In addition, as a combination of a high-conductivity liquid and a low-conductivity liquid, a combination of _CO2 water and DIW was exemplified, but in addition, a combination of _NH3 water and DIW, and an aqueous _NH4OH solution (1:100) were also used. and DIW, a combination of H ₂ SO ₄ aqueous solution and DIW, a combination of HCl aqueous solution (1:50) and DIW, a combination of HF aqueous solution (1:500) and DIW, and the like.

Also, as the first to third substrate processing examples, the cleaning processing for cleaning the substrate W is taken as an example, but the present invention can also be applied to the etching processing for etching the substrate W using an etchant.
In the above-described embodiment, the case where the substrate processing apparatus 1 is an apparatus for processing the surface of the substrate W made of a semiconductor wafer has been described. An apparatus for processing substrates such as FPD (Flat Panel Display) substrates such as display devices, optical disk substrates, magnetic disk substrates, magneto-optical disk substrates, photomask substrates, ceramic substrates, solar cell substrates, etc. good too. However, the effect of the present invention is particularly remarkable when the surface of the substrate W exhibits hydrophobicity.

In addition, various design changes can be made within the scope of the matters described in the claims.

Reference Signs List 1: substrate processing apparatus 3: control device 4: processing chamber 5: spin chuck (substrate holding unit)
30: top nozzle (low conductive liquid supply unit)
37: DIW upper pipe (low conductive liquid supply unit)
42: DIW upper valve (low conductive liquid supply unit)
50: bottom nozzle (highly conductive liquid supply unit)

Claims (11)

A method of treating a substrate by supplying a chemical solution to the surface of the substrate on which a pattern is formed, comprising:
a substrate holding step of holding the substrate;
a chemical solution supply step of supplying the chemical solution to the surface of the substrate;
Prior to the chemical solution supply step, a low-conductivity liquid valve is opened to remove charges accumulated on the outer surface of the pattern, and a low-conductivity liquid having a lower conductivity than the chemical solution is supplied to the low-conductivity liquid. a low-conductivity liquid supply step of supplying the low-conductivity liquid from the low-conductivity liquid nozzle to the patterned surface of the substrate by supplying the low-conductivity liquid from a liquid supply source to the low-conductivity liquid nozzle;
Prior to the step of supplying the low-conductivity liquid, a high-conductivity liquid having a conductivity lower than that of the chemical liquid and higher than that of the low-conductivity liquid is added to the low-conductivity liquid in order to reduce the charge accumulated in the pattern. By opening a high conductivity liquid valve different from the conductive liquid valve and supplying the high conductivity liquid nozzle from a high conductivity liquid supply different from the low conductivity liquid supply to the high conductivity liquid nozzle, the and a highly conductive liquid supplying step of supplying a highly conductive liquid to the back surface of the substrate opposite to the patterned surface. 2. The substrate according to claim 1, further comprising 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. Processing method. 3. The substrate processing method according to claim 1, wherein liquid is not supplied to said surface of said substrate in parallel with said step of supplying highly conductive liquid. In parallel with the step of supplying the highly conductive liquid, a facing member having a substrate-facing surface facing the entire surface of the substrate is arranged at a close position such that the substrate-facing surface is close to the surface of the substrate. The substrate processing method according to any one of claims 1 to 3, further comprising a positioning step. After the low-conductivity liquid supply step and prior to the chemical liquid supply step, a second high-conductivity liquid supply step of supplying the high-conductivity liquid to at least the surface of the substrate to neutralize the substrate. The substrate processing method according to any one of claims 1 to 4, comprising The substrate holding step includes
6. The substrate processing method according to claim 1, further comprising the step of holding the substrate by bringing a conductive portion formed using a conductive material into contact with the peripheral portion of the substrate. The substrate processing method of any one of claims 1-6, wherein the low-conductivity liquid comprises deionized water. The substrate processing method according to any one of claims 1 to 7, wherein the highly conductive liquid includes a liquid containing ions. a substrate holding unit that holds a substrate having a pattern formed on its surface;
a chemical liquid supply unit for supplying a conductive chemical liquid 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 lower conductivity than the chemical solution to the surface of the substrate held by the substrate holding unit;
a low-conductivity liquid supply for supplying the low-conductivity liquid to the low-conductivity liquid nozzle;
a low-conductivity liquid valve that switches between supplying and stopping the supply of the low-conductivity liquid from the low-conductivity liquid supply source to the low-conductivity liquid nozzle;
high conductivity 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 the back surface of the substrate held by the substrate holding unit opposite to the front surface; a liquid nozzle;
a highly conductive liquid supply, different from the low-conductivity liquid supply, for supplying the high-conductivity liquid to the high-conductivity liquid nozzle;
A high-conductivity liquid valve for switching between supplying and stopping the supply of the high-conductivity liquid from the high-conductivity liquid supply source to the high-conductivity liquid nozzle, the high-conductivity liquid being different from the low-conductivity liquid valve. a valve;
a control device that controls the chemical supply unit, the low-conductivity liquid valve, and the high-conductivity liquid valve;
a chemical solution supplying step for supplying the chemical solution to the surface of the substrate; a low-conductivity liquid supply step of opening the substrate and supplying the low-conductivity liquid by the low-conductivity liquid nozzle to the patterned surface of the substrate; and prior to the low-conductivity liquid supply step, The highly conductive liquid valve is opened and the highly conductive liquid nozzle directs the highly conductive liquid away from the patterned surface of the substrate to reduce the charge build-up on the pattern. and a step of supplying a highly conductive liquid to the back surface on the opposite side. a facing member having a substrate-facing surface that faces the entire surface of the substrate held by the substrate holding unit, the substrate-facing surface being arranged at a position close to the surface of the substrate; The substrate processing apparatus according to claim 9. 11. The substrate processing apparatus according to claim 9, wherein said substrate holding unit has holding pins for contacting and supporting the periphery of the substrate, said holding pins being made of a conductive material.

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