JP2016072609A - Wafer processing method and wafer processing apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a wafer processing method capable of efficiently excluding a processing liquid residual within a processing liquid nozzle and processing liquid piping by introducing a gas while preventing the gas from being blown to a wafer, and a wafer processing apparatus.SOLUTION: A wafer processing method executes: liquid medicine discharge steps (S3 and S4) of discharging a liquid medicine from the processing liquid nozzle towards the wafer by leading the liquid medicine into the processing liquid piping; gas extrusion steps (S5 and S6) of extruding the processing liquid within the processing liquid piping and the processing liquid nozzle towards the outside by introducing a nitrogen gas from a fluid introduction part into the processing liquid piping after the liquid medicine discharge steps are stopped; and a gas introduction stop step (S6) of stopping introducing the gas into the processing liquid piping in the state where the processing liquid is residual in a tip of the processing liquid nozzle after the introduction of the gas is started.SELECTED DRAWING: Figure 3

Description

  The present invention relates to a method and apparatus for performing processing using a processing liquid on a substrate to be processed. Substrates to be processed include semiconductor wafers, glass substrates for liquid crystal display devices, plasma display substrates, FED (Field Emission Display) substrates, photomask substrates, optical disk substrates, magnetic disk substrates, and magneto-optical disk substrates. , Ceramic substrates, solar cell substrates and the like.

  In a manufacturing process of a semiconductor device or a liquid crystal display device, processing using a processing liquid such as a chemical liquid or a rinsing liquid is performed on a substrate such as a semiconductor wafer or a glass substrate for a liquid crystal display panel. A single-wafer type substrate processing apparatus that performs processing using a processing liquid on a substrate one by one, a spin chuck that rotates while holding the substrate substantially horizontal, and processing on the substrate held by the spin chuck And a treatment liquid nozzle for supplying a liquid. A processing liquid pipe is connected to the processing liquid nozzle.

  Patent Document 1 below discloses a configuration in which nitrogen is introduced into a processing liquid pipe via a mixing valve in order to prevent dripping of the processing liquid from the processing liquid nozzle. With the nitrogen introduced into the processing liquid pipe, the processing liquid existing inside the processing liquid nozzle and inside the processing liquid pipe is extruded and discharged from the processing liquid nozzle. The introduction of nitrogen into the processing liquid piping is continued until the processing liquid is completely discharged from the processing liquid nozzle and the processing liquid piping.

JP 2005-302746 A

However, the extrusion process by introducing nitrogen has a problem that damage to the substrate occurs when gas (nitrogen gas) is blown onto the substrate (semiconductor wafer).
That is, when there is no processing liquid remaining in the processing liquid piping and the processing liquid nozzle, only the gas is discharged from the discharge port of the processing liquid nozzle, and the gas is blown directly onto the substrate. If the gas is blown onto the substrate, the processing quality of the substrate may be degraded.

More specifically, when the gas is blown to the substrate, the vicinity of the center of the substrate is dried, or the liquid droplets of the chemical liquid are scattered, resulting in deterioration of the uniformity of the chemical processing or generation of particles on the substrate. There is a risk.
SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a substrate processing method and a substrate processing apparatus capable of efficiently removing the processing liquid remaining inside the processing liquid nozzle and the processing liquid piping by introducing gas while avoiding the gas being blown to the substrate. Is to provide.

  The invention described in claim 1 for achieving the above object is a substrate processing method for performing a process using a processing liquid on a substrate to be processed, the substrate holding rotation mechanism A substrate holding step for holding the substrate in a horizontal posture, and introducing a processing liquid into the processing liquid pipe from a fluid introduction part at the other end of the processing liquid pipe provided with a processing liquid nozzle having a discharge port at one end. The process liquid discharge step of discharging the process liquid from the discharge port toward the substrate, and introducing the gas into the process liquid pipe from the fluid introduction part after the process liquid discharge step is stopped. A gas extruding step for extruding the processing liquid in the liquid pipe and the processing liquid nozzle outward, and after the start of the introduction of the gas, the processing liquid remains in the processing liquid pipe and / or the processing liquid nozzle. Above in the state And a gas introduction stopping step of stopping the introduction of gas into physical fluid in the pipe, to provide a substrate processing methods.

  According to this method, after the discharge of the processing liquid from the discharge port of the processing liquid nozzle to the substrate is stopped, the gas is introduced into the processing liquid pipe from the fluid introduction portion, thereby allowing the processing liquid pipe and the processing liquid nozzle to be introduced. The inner treatment liquid is extruded outward (gas extrusion process). In this case, in a state where the processing liquid remains in the processing liquid piping and / or the processing liquid nozzle, in other words, before the processing liquid is completely pushed out from the processing liquid piping and the processing liquid nozzle, The introduction of gas into the processing liquid piping is stopped. Therefore, in the gas extrusion process, it is possible to prevent the gas introduced into the processing liquid piping from being directly blown onto the substrate.

In addition, after the gas extrusion process is completed, the processing liquid remains at least at the tip of the processing liquid nozzle. Since this processing liquid serves as a lid for the processing liquid nozzle, it is possible to prevent gas from leaking through the discharge port of the processing liquid nozzle.
According to a second aspect of the present invention, in the gas introduction stopping step, the introduction of the gas into the processing liquid pipe is stopped in a state where the processing liquid remains at the tip of the processing liquid nozzle. 1. The substrate processing method according to 1.

  According to this method, the introduction of the gas into the processing liquid pipe is stopped while the processing liquid remains at the tip of the processing liquid nozzle. Since the processing liquid remaining in the portion of the processing liquid pipe and the processing liquid nozzle other than the tip of the processing liquid nozzle is removed, after the gas extrusion step is completed, the processing liquid piping and the processing liquid nozzle are mostly used. There is no processing solution. Thereby, dripping of the processing liquid from the discharge port of the processing liquid nozzle can be effectively suppressed.

The invention according to claim 3 further includes a processing liquid recovery step of recovering the processing liquid removed from the substrate from the recovery flow path in parallel with the gas extrusion step. It is a processing method.
According to this method, the processing liquid discharged from the discharge port of the processing liquid nozzle to the substrate by the gas extrusion process can be recovered from the recovery flow path while avoiding adverse effects due to the gas being blown to the substrate. Some chemical solutions used in semiconductor manufacturing processes and the like are expensive, and such chemical solutions are sometimes used as processing solutions. In this case, since the chemical liquid remaining in the processing liquid piping and the processing liquid nozzle can be recovered, the operation cost can be reduced.

According to a fourth aspect of the present invention, the processing liquid includes a chemical solution, and the substrate processing method is configured to introduce a rinsing liquid into the processing liquid pipe from the fluid introduction portion after the gas introduction stop step. The substrate processing method according to claim 1, further comprising a rinsing liquid discharge step of discharging the rinsing liquid from the discharge port toward the substrate.
According to the present invention, the chemical liquid is introduced into the processing liquid piping for discharging the chemical liquid from the processing liquid nozzle, and the gas extruding step is executed after the discharge. Further, following the gas extrusion step, a rinsing liquid is introduced into the processing liquid piping, and the rinsing liquid is discharged from the discharge port of the processing liquid nozzle. In this case, the gas extrusion step is performed after the treatment using the chemical solution and before the treatment using the rinse solution is started. Nevertheless, no gas is blown onto the substrate. Therefore, various adverse effects due to the gas being blown onto the substrate can be avoided.

  In this case, the chemical liquid and the gas remaining in the processing liquid nozzle and / or the processing liquid pipe are sprayed on the substrate together with the rinsing liquid at the start of the rinsing liquid discharging step. Since the treatment liquid is relatively small and the chemical liquid is diluted by the subsequent rinsing liquid, there is almost no adverse effect on the substrate due to the supply of the residual chemical liquid. Further, the pressure of the gas remaining in the processing liquid pipe and the processing liquid nozzle is not high, and therefore, when this gas is blown onto the substrate, adverse effects such as drying and contamination of the substrate can be substantially ignored.

  In order to achieve the above object, an invention according to claim 5 is directed to a substrate holding and rotating mechanism for rotating while holding a substrate in a horizontal posture, and toward the substrate held by the substrate holding and rotating mechanism. A treatment liquid nozzle having a discharge port for discharging the treatment liquid at the tip; a treatment liquid pipe provided with the treatment liquid nozzle at one end; and a fluid introduction portion for introducing the treatment liquid at the other end; and the fluid introduction A treatment liquid supply pipe for supplying a treatment liquid to the treatment liquid pipe, a treatment liquid valve for opening and closing the treatment liquid pipe, and a gas introduction section connected to the fluid introduction part. A gas pipe, a gas valve that opens and closes the processing liquid pipe, and the processing liquid valve is opened to introduce the processing liquid into the processing liquid pipe from the fluid introduction portion, thereby supplying the processing liquid from the discharge port to the substrate. Discharged toward After the liquid discharge step and the processing liquid valve are closed and the processing liquid discharge step is stopped, the gas valve is opened and gas is introduced into the processing liquid pipe from the fluid introduction part, thereby the processing liquid pipe A state in which the processing liquid remains in the processing liquid pipe and / or the processing liquid nozzle after the gas extrusion process for extruding the processing liquid in the processing liquid nozzle and the processing liquid nozzle to the outside and the introduction of the gas A substrate processing apparatus is provided, comprising: a control unit that performs a gas introduction stop step of stopping the introduction of the gas into the processing liquid pipe by opening the gas valve.

  According to this configuration, after the discharge of the processing liquid from the discharge port of the processing liquid nozzle to the substrate is stopped, the gas is introduced into the processing liquid pipe from the fluid introduction unit, thereby allowing the processing liquid pipe and the processing liquid nozzle to be introduced. The inner treatment liquid is extruded outward (gas extrusion process). In this case, in a state where the processing liquid remains in the processing liquid piping and / or the processing liquid nozzle, in other words, before the processing liquid is completely pushed out from the processing liquid piping and the processing liquid nozzle, The introduction of gas into the processing liquid piping is stopped. Therefore, in the gas extrusion process, it is possible to prevent the gas introduced into the processing liquid piping from being directly blown onto the substrate.

In addition, after the gas extrusion process is completed, the processing liquid remains at least at the tip of the processing liquid nozzle. Since this processing liquid serves as a lid for the processing liquid nozzle, it is possible to prevent gas from leaking through the discharge port of the processing liquid nozzle.
According to a sixth aspect of the present invention, in the control unit according to the fifth aspect, the control unit stops the introduction of gas into the processing liquid pipe in a state where the processing liquid remains at the tip of the processing liquid nozzle. It is a substrate processing apparatus of description.

  According to this configuration, the introduction of the gas into the processing liquid pipe is stopped while the processing liquid remains at the tip of the processing liquid nozzle. Since the processing liquid remaining in the portion of the processing liquid pipe and the processing liquid nozzle other than the tip of the processing liquid nozzle is removed, after the gas extrusion step is completed, the processing liquid piping and the processing liquid nozzle are mostly used. There is no processing solution. Thereby, dripping of the processing liquid from the discharge port of the processing liquid nozzle can be effectively suppressed.

A seventh aspect of the present invention is the substrate processing apparatus according to the fifth or sixth aspect, further comprising a pressurized gas tank capable of containing a gas and interposed in the gas pipe.
According to this configuration, since the pressurized gas tank that can accommodate gas and is disposed on the gas pipe is provided, the amount of gas introduced into the processing liquid pipe can be reduced by using the pressurized tank. It can be controlled with high accuracy.

According to an eighth aspect of the present invention, the apparatus may further include a rinsing liquid pipe that is connected to the fluid introduction part and supplies a rinsing liquid to the processing liquid pipe.
The invention according to claim 9 is the substrate processing apparatus according to any one of claims 5 to 8, further comprising a processing liquid recovery mechanism that guides the processing liquid pushed toward the substrate to the recovery flow path. is there.
According to this method, the processing liquid discharged from the processing liquid nozzle onto the substrate can be recovered from the recovery flow path by the gas extrusion step while avoiding the adverse effect of the gas being blown onto the substrate. Some chemical solutions used in semiconductor manufacturing processes and the like are expensive, and when such a chemical solution is used as a treatment solution, the chemical solution remaining in the treatment solution piping and the treatment solution nozzle can be recovered. For this reason, it becomes possible to reduce the operating cost of the apparatus.

  As described in claim 10, an opening degree adjusting valve for adjusting the opening degree of the gas pipe may be further included. In this case, the control unit may store a recipe, and the control unit may open and close the gas valve and adjust the opening of the opening adjustment valve based on the recipe.

FIG. 1 is a schematic diagram of a substrate processing apparatus according to an embodiment of the present invention. FIG. 2 is a schematic view of a main part of the substrate processing apparatus according to one embodiment of the present invention. FIG. 3 is a flowchart for explaining wafer processing by the substrate processing apparatus shown in FIGS. FIG. 4A is a longitudinal cross-sectional view of the pretreatment liquid nozzle after the gas extrusion step is completed. FIG. 4B is a view as seen from the section line IVB-IVB in FIG. 4A. FIG. 5A is a vertical cross-sectional view of the upper treatment liquid nozzle after completion of the gas extrusion step. FIG. 5B is a view as seen from the cutting plane line VB-VB in FIG. 5A. FIG. 6 is a schematic cross-sectional view of a main part of a substrate processing apparatus according to another embodiment. FIG. 7 is a schematic cross-sectional view of a main part of a substrate processing apparatus according to still another embodiment. FIG. 8 is a diagram illustrating a main part of a substrate processing apparatus according to a modification.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.
FIG. 1 is a schematic diagram of a substrate processing apparatus 1 according to an embodiment of the present invention. FIG. 2 is a schematic diagram of the substrate processing apparatus 1 according to an embodiment of the present invention. FIG. 1 shows a case where the splash guard 4 is in the raised position, and FIG. 2 shows a case where the splash guard 4 is in the lowered position.

The substrate processing apparatus 1 is a single-wafer type apparatus that processes a disk-shaped substrate W such as a semiconductor wafer W (hereinafter simply referred to as “wafer W”) one by one with a processing liquid (chemical solution and rinsing liquid). is there.
The substrate processing apparatus 1 includes a box-shaped chamber 2 having an internal space, and a vertical rotation axis that passes through the center of the wafer W while holding a single wafer W in a substantially horizontal posture. A spin chuck 3 for rotating the wafer W around and an annular splash guard 4 arranged so as to surround the spin chuck 3 in plan view.

  The spin chuck 3 is a disc-shaped spin base 5 that is disposed substantially horizontally, and a rotation shaft that is attached substantially vertically to the spin base 5 at the center of the lower surface of the spin base 5 and has a central axis that extends substantially vertically. 6 is provided. A plurality of chuck pins 7 are arranged on the periphery of the upper surface of the spin base 5 at intervals on a circumference corresponding to the outer peripheral shape of the wafer W. The chuck pins 7 support the peripheral edge of the wafer W, abut on the end surface (peripheral surface) of the wafer W, and can hold the wafer W in cooperation with other chuck pins 7. The wafer W is held by the spin chuck 3 so that the center axis thereof coincides with the center axis of the rotary shaft 6.

  The rotation shaft 6 is coupled to a lower rotation drive mechanism 8 for rotating the rotation shaft 6 about its central axis. The wafer W held on the spin chuck 3 by the lower rotation drive mechanism 8 is substantially horizontal. It can be rotated in a simple plane. The lower rotation drive mechanism 8 is disposed below the spin base 5 and is protected from the treatment liquid (chemical liquid and rinse liquid) by the hood 9. The rotating shaft 6 has a tubular shape, and a lower processing liquid pipe 10 is inserted into the rotating shaft 6 for flowing a processing liquid. A gap forming a nitrogen gas supply path 11 is formed between the inner wall surface of the rotating shaft 6 and the pretreatment liquid pipe 10. The upper end of the nitrogen gas supply path 11 is opened as a nitrogen gas discharge port 11 a between the spin base 5 and the pretreatment liquid pipe 10.

Nitrogen gas (an example of an inert gas) from a nitrogen gas supply source 13 can be introduced from below the nitrogen gas supply path 11 through the nitrogen gas pipe 12. A valve 12V is interposed in the nitrogen gas pipe 12. Nitrogen gas can be discharged from the nitrogen gas discharge port 11a by opening the valve 12V.
One end of the lower treatment liquid pipe 10 slightly protrudes from the upper surface of the spin base 5, and this protrusion constitutes a lower treatment liquid nozzle 14 that discharges the treatment liquid. A flange 15 is provided on the peripheral edge of the tip of the pretreatment liquid nozzle 14. The flange 15 covers the upper side of the nitrogen gas discharge port 11a, so that the processing liquid discharged from the lower processing liquid nozzle 14 does not enter the nitrogen gas discharge port 11a.

  The other end of the lower processing liquid pipe 10 forms a fluid introduction part 10a for introducing a processing liquid and nitrogen gas. A mixing valve MV1 is connected to the fluid introduction part 10a. A chemical liquid pipe 16, a rinse liquid pipe 17, and a nitrogen gas pipe 18 are connected to the mixing valve MV1. The inside of the pretreatment liquid pipe 10, the inside of the chemical liquid pipe 16, the inside of the rinsing liquid pipe 17, and the inside of the nitrogen gas pipe 18 are communicated with each other through the inside of the mixing valve MV1. A chemical liquid supply source 19 containing a chemical liquid is connected to the chemical liquid pipe 16, and a rinse liquid supply source 20 containing a rinse liquid (for example, pure water such as deionized water) is connected to the rinse liquid pipe 17. Is connected. A nitrogen gas supply source 13 is connected to the nitrogen gas pipe 18.

  The chemical liquid supplied from the chemical liquid supply source 19 to the chemical liquid pipe 16 is, for example, sulfuric acid, acetic acid, nitric acid, hydrochloric acid, hydrofluoric acid, aqueous ammonia, hydrogen peroxide, organic acid (for example, citric acid, oxalic acid, etc.), organic alkali ( For example, a liquid containing TMAH: tetramethylammonium hydroxide, etc., an organic solvent (eg, IPA: isopropyl alcohol, etc.), and at least one of a surfactant and a corrosion inhibitor.

  A valve 16V1 is interposed in the chemical solution pipe 16 in the vicinity of the connection portion with the mixing valve MV1. By opening the valve 16V1, the chemical liquid flowing through the chemical liquid pipe 16 can be introduced into the pretreatment liquid pipe 10 via the mixing valve MV1. A valve 17V1 is interposed in the rinsing liquid pipe 17 in the vicinity of the connection portion with the mixing valve MV1. By opening the valve 17V1, the rinse liquid flowing through the rinse liquid pipe 17 can be introduced into the pretreatment liquid pipe 10 through the mixing valve MV1. A valve 18V1 is interposed in the nitrogen gas pipe 18 in the vicinity of the connection portion with the mixing valve MV1. By opening the valve 18V1, the rinse liquid flowing through the nitrogen gas pipe 18 can be introduced into the pretreatment liquid pipe 10 via the mixing valve MV1. Nitrogen gas can be introduced into the processing liquid pipe 10. With the valves 16V1, 17V1, and 18V1, the fluid introduced into the processing liquid pipe 10 can be switched between the chemical liquid, the rinsing liquid, and the nitrogen gas.

  By opening the valve 16V1 while closing the valves 17V1 and 18V1, only the chemical liquid is supplied into the lower processing liquid pipe 10, and the chemical liquid is discharged from the lower processing liquid nozzle 14. By opening the valve 17V1 while closing the valves 16V1 and 18V1, only the rinsing liquid is supplied into the lower processing liquid pipe 10, and the rinsing liquid is discharged from the lower processing liquid nozzle 14. By opening the valve 18V1 while closing the valves 16V1 and 17V1, only the nitrogen gas is supplied into the pretreatment liquid pipe 10. In the state where the processing liquid exists inside the lower processing liquid pipe 10 and the lower processing liquid nozzle 14 (hereinafter referred to as “inside the lower processing liquid pipe 10 and the lower processing liquid nozzle 14”), the lower processing liquid pipe 10 By supplying nitrogen gas into the inside, the processing liquid in the processing liquid pipe 10 and the lower processing liquid nozzle 14 can be pushed out by the nitrogen gas and discharged from the lower processing liquid nozzle 14.

  The valve 18V1 includes a valve body in which a valve seat is provided, a valve body that opens and closes the valve seat, and an actuator that moves the valve body between an open position and a closed position. By moving the valve body between the open position and the closed position, the opening and closing of the valve 18V1 is switched. Further, the opening degree of the valve 18V1 (the gap between the valve body in the open position and the valve seat) can be changed by changing the position of the valve body in the open position. By adjusting the opening degree of the valve 18V1, the flow rate of the nitrogen gas supplied to the pretreatment liquid piping 10 can be adjusted.

Above the spin chuck 3, a disc-shaped blocking plate 21 having substantially the same diameter as the wafer W or a larger diameter than the wafer W is disposed substantially horizontally. At the center of the upper surface of the shielding plate 21, a rotating shaft 22 having a central axis extending substantially perpendicularly to the shielding plate 21 is attached. The central axis of the rotating shaft 22 and the central axis of the rotating shaft 6 are substantially on the same straight line.
A lower rotation drive mechanism 23 is coupled to the rotation shaft 22. By means of the lower rotation drive mechanism 23, the blocking plate 21 can be rotated at substantially the same rotational speed in the same direction as the spin chuck 3 in a substantially horizontal plane.

The rotating shaft 22 is tubular, and a processing liquid pipe 24 for flowing a processing liquid is inserted into the rotating shaft 22. A gap forming a nitrogen gas supply path 26 is formed between the inner wall surface of the rotating shaft 22 and the processing liquid pipe 24. A lower end of the nitrogen gas supply path 26 is opened as a nitrogen gas discharge port 26 a between the blocking plate 21 and the processing liquid pipe 24.
Nitrogen gas (an example of an inert gas) from the nitrogen gas supply source 13 can be introduced from above the nitrogen gas supply path 26 via the nitrogen gas pipe 27. The nitrogen gas pipe 27 is provided with a valve 27V. By opening the valve 27V, nitrogen gas can be discharged from the nitrogen gas discharge port 26a.

One end of the processing liquid pipe 24 constitutes an upper processing liquid nozzle 25 that is disposed substantially flush with the lower surface of the blocking plate 21 and discharges the processing liquid.
The other end of the treatment liquid pipe 24 forms a fluid introduction part 24a for introducing treatment liquid and nitrogen gas. A mixing valve MV2 is connected to the fluid introduction part 24a. A chemical liquid pipe 16, a rinse liquid pipe 17, and a nitrogen gas pipe 18 are connected to the mixing valve MV2. The inside of the processing liquid pipe 24 communicates with the inside of the chemical liquid pipe 16, the inside of the rinsing liquid pipe 17, and the inside of the nitrogen gas pipe 18 via the inside of the mixing valve MV2.

  A valve 16V2 is interposed in the chemical solution pipe 16 in the vicinity of the connection portion with the mixing valve MV2. By opening the valve 16V2, the chemical liquid flowing through the chemical liquid pipe 16 can be introduced into the upper processing liquid pipe 24 via the mixing valve MV2. The rinsing liquid pipe 17 is provided with a valve 17V2 in the vicinity of the connection portion with the mixing valve MV1. By opening the valve 17V2, the rinsing liquid flowing through the rinsing liquid pipe 17 can be introduced into the upper processing liquid pipe 24 via the mixing valve MV2. A valve 18V2 is interposed in the nitrogen gas pipe 18 in the vicinity of the connection portion with the mixing valve MV2. Nitrogen gas can be introduced into the processing liquid pipe 24 by opening the valve 18V2. With the valves 16V2, 17V2, and 18V2, the fluid introduced into the processing liquid pipe 24 can be switched between the chemical liquid, the rinsing liquid, and the nitrogen gas.

  By opening the valve 16V2 while closing the valves 17V2 and 18V2, only the chemical liquid is supplied into the upper processing liquid pipe 24, and the chemical liquid is discharged from the upper processing liquid nozzle 25. By opening the valve 17V2 while closing the valves 16V2 and 18V2, only the rinse liquid is supplied into the upper process liquid pipe 24, and the rinse liquid is discharged from the upper process liquid nozzle 25. By opening the valve 18V2 while closing the valves 16V2 and 17V2, only the nitrogen gas is supplied into the upper processing liquid pipe 24. The upper processing liquid pipe 24 is in a state where the processing liquid exists inside the upper processing liquid pipe 24 and the upper processing liquid nozzle 25 (hereinafter referred to as “inside the upper processing liquid pipe 24 and the upper processing liquid nozzle 25”). By supplying nitrogen gas into the inside, the processing liquid in the processing liquid pipe 24 and the upper processing liquid nozzle 25 can be pushed out by the nitrogen gas and discharged from the upper processing liquid nozzle 25.

  The valve 18V2 includes a valve body in which a valve seat is provided, a valve body that opens and closes the valve seat, and an actuator that moves the valve body between an open position and a closed position. By moving the valve body between the open position and the closed position, the opening and closing of the valve 18V2 is switched. Further, by changing the position of the valve body in the open position, the opening degree of the valve 18V2 (the gap between the valve body in the open position and the valve seat) can be changed. By adjusting the opening degree of the valve 18V2, the flow rate of the nitrogen gas supplied to the upper processing liquid pipe 24 can be adjusted.

An upper elevating mechanism 33 is coupled to the rotary shaft 22 and the processing liquid pipe 24. The rotating shaft 22 and the processing liquid pipe 24 can be lifted and lowered simultaneously by the upper lifting mechanism 33.
At the lower part of the splash guard 4, a notch-shaped first guide part 4a opened obliquely downward on the center axis side of the splash guard 4, and an annular shape engraved in the vertical direction inside the first guide part 4a A groove 4 c is formed over the entire circumference of the splash guard 4. Further, on the inner surface (center axis side) upper portion of the splash guard 4, a groove-shaped second guide portion 4 b opened in a V shape toward the inner side (rotation axis side of the spin chuck 3) in the horizontal direction is formed. ing.

Below the splash guard 4, three cylindrical members 28 a, 28 b and 28 c are erected coaxially on the bottom plate 36. The diameter of the cylindrical member 28a is larger than the diameters of the cylindrical members 28b and 28c, and the diameter of the cylindrical member 28b is larger than the diameter of the cylindrical member 28c. The cylindrical member 28a has a size capable of accommodating the splash guard 4 therein.
A first recovery tank (recovery flow path) 30 is formed with the cylindrical member 28a and the cylindrical member 28b as side walls, and a second recovery tank 29 is formed with the cylindrical member 28b and the cylindrical member 28c as side walls. First and second drainage pipes 32 and 31 for draining the liquid inside are connected to the bottoms of the first and second recovery tanks 30 and 29, respectively.

A lower elevating mechanism 34 is coupled to the splash guard 4 so that the splash guard 4 can be held at an arbitrary height position. Thereby, the splash guard 4 can be moved up and down between the raised position (position shown in FIG. 1) and the lowered position (position shown in FIG. 2).
As shown in FIG. 1, when the splash guard 4 is in the raised position, the first guide portion 4 a is positioned on the side of the wafer W held by the spin chuck 3. In this state, the processing liquid (chemical liquid or rinsing liquid) supplied from the lower processing liquid nozzle 14 and / or the upper processing liquid nozzle 25 to the wafer W held by the spin chuck 3 and rotated by the lower rotation driving mechanism 8 is In response to the centrifugal force of the rotating wafer W, the wafer W scatters to the side and is received by the first guide portion 4a. The processing liquid that has landed on the first guide portion 4a is guided to the first flow path P1, flows down due to its own weight, and is guided to the first recovery tank 30 through the first flow path P1. Thereby, the processing liquid removed from the wafer W is recovered in the first recovery tank 30.

On the other hand, as shown in FIG. 2, when the splash guard 4 is in the lowered position, the splash guard 4 is substantially accommodated inside the cylindrical member 28a, and the annular groove 4c of the splash guard 4 fits in the upper part of the cylindrical member 28b. It is like that. At this time, the second guide portion 4 b is located on the side of the wafer W held by the spin chuck 3.
In this state, the processing liquid supplied from the lower processing liquid nozzle 14 and / or the upper processing liquid nozzle 25 to the wafer W held by the spin chuck 3 and rotated by the lower rotation driving mechanism 8 is applied to the rotating wafer W. It receives centrifugal force and scatters to the side and is received by the second guide portion 4b. The processing liquid that has landed on the second guide portion 4b is guided to the second flow path P2, flows down downward by its own weight, and is guided to the second recovery tank 29 through the second flow path P2. As a result, the processing liquid removed from the wafer W is recovered in the second recovery tank 29.

  As described above, by raising and lowering the splash guard 4, it is possible to switch the destination of the processing liquid scattered from the peripheral edge of the wafer W between the first flow path P <b> 1 and the second flow path P <b> 2. The processing liquid can be separated and discharged from the first and second drainage pipes 32 and 31. In the processing executed in the substrate processing apparatus 1, the processing liquid recovered in the second recovery tank 29 is discarded after passing through the first drainage pipe (recovery flow path) 32 and recovered in the first recovery tank 30. The treated liquid passes through the second drainage pipe 31 and is reused.

  Hereinafter, the rising position of the splash guard 4 (position shown in FIG. 1), that is, the position of the splash guard 4 where the processing liquid removed from the wafer W held by the spin chuck 3 is guided to the first recovery tank 30. A splash position where the splash guard 4 is lowered (position shown in FIG. 1), that is, the processing liquid removed from the wafer W held by the spin chuck 3 is guided to the second recovery tank 29, which is called “recovery position”. The position of the guard 4 is called “discard position”.

  The substrate processing apparatus 1 includes a control unit 35. The control unit 35 includes a computer. The control unit 35 includes a storage device (not shown). The control unit 35 stores a recipe (program) for performing substrate processing. The control unit 35 controls the operations of the rotation drive mechanisms 8 and 23 and the lifting mechanisms 33 and 34 based on the contents of the recipe stored in the control unit 35. The control unit 35 opens and closes the valves 12V, 16V1, 16V2, 17V1, 17V2, 18V1, 18V2, and 27V based on the contents of the recipe stored in the control unit 35. Furthermore, the control unit 35 adjusts the opening degree of 18V1 and 18V2 based on the contents of the recipe stored in the control unit 35.

In the present invention, the opening and closing timing and the opening degree of the valve 18V1 are set such that, as will be described later, when the processing liquid in the lower processing liquid pipe 10 and the lower processing liquid nozzle 14 is pushed out by nitrogen gas, the upper processing liquid pipe 24 and the lower opening 18 Control is performed so that the processing liquid in the processing liquid nozzle 14 is not completely removed.
In the present invention, the opening / closing timing and the opening degree of the valve 18V2 are set such that the processing liquid in the upper processing liquid pipe 24 and the upper processing liquid nozzle 25 is pushed out by nitrogen gas, as will be described later. Control is performed so that the processing liquid in the processing liquid nozzle 25 is not completely removed.

FIG. 3 is a flowchart for explaining a wafer W processing method by the substrate processing apparatus 1. The substrate processing will be described with reference to FIGS.
The control unit 35 closes the valves 16V1, 16V2, 17V1, 17V2, 18V1, and 18V2 and opens the valves 12V and 27V. Thus, the processing liquid is not discharged from the lower processing liquid nozzle 14 and the upper processing liquid nozzle 25, but nitrogen gas is discharged from the nitrogen gas discharge ports 11a and 26a. Nitrogen gas is discharged at a flow rate of about 50 liters / min to 100 liters / min, for example. In this state, there is no liquid such as the rinsing liquid in the processing liquid pipes 10, 24, the lower processing liquid nozzle 14 and the upper processing liquid nozzle 25. Moreover, the splash guard 4 is arrange | positioned in the position further lowered | hung below from the discard position (refer FIG. 2).

In this state, an unprocessed wafer W is loaded into the chamber 2 by a robot hand (not shown) (step S1), and the wafer W is held in a substantially horizontal posture by the spin chuck 3.
Thereafter, the control unit 35 controls the lower elevating mechanism 34 to raise the splash guard 4 toward the collection position (see FIG. 1). (Step S2) Further, the control unit 35 controls the lower rotation driving mechanism 8 to rotate the wafer W held by the spin chuck 3 around a predetermined rotation axis.

  Next, the control unit 35 opens the valves 16V1 and 16V2. Thereby, a chemical | medical solution is introduce | transduced in the process liquid piping 10 and 24 from the fluid introduction parts 10a and 24a (step S3). Thereby, the chemical liquid is discharged toward the wafer W from the lower processing liquid nozzle 14 and the upper processing liquid nozzle 25 (chemical liquid discharging process (processing liquid discharging process)). The chemical solution discharged from the pretreatment liquid nozzle 14 is supplied to the vicinity of the central portion of the lower surface of the wafer W held by the spin chuck 3 and receives the centrifugal force due to the rotation of the wafer W, so that the lower surface of the wafer W becomes the peripheral portion. Spread towards. The chemical solution discharged from the upper processing liquid nozzle 25 is supplied to the vicinity of the center portion of the upper surface of the wafer W held by the spin chuck 3 and receives the centrifugal force due to the rotation of the wafer W, so that the upper surface of the wafer W becomes the peripheral portion. Spread towards. Thereby, the entire lower surface of the wafer W and the entire upper surface of the wafer W are uniformly processed with the chemical solution.

  The chemical solution that has reached the peripheral edge of the wafer W receives the centrifugal force of the rotating wafer W, scatters to the side, and is received by the first guide portion 4a. The chemical liquid that has landed on the first guide portion 4 a flows down and is collected in the first collection tank 30. No liquid such as a rinsing liquid exists in the processing liquid pipes 10 and 24, the lower processing liquid nozzle 14 and the upper processing liquid nozzle 25 before the chemical liquid is introduced. Therefore, other liquids such as a rinsing liquid are not mixed in the chemical liquid recovered in the first recovery tank 30.

When a predetermined time elapses from the introduction of the chemical liquid into the treatment liquid pipes 10 and 24, the control unit 35 closes the valves 16V1 and 16V2. Thereby, the introduction of the chemical liquid into the processing liquid pipes 10 and 24 is stopped (step S4). In this state, the chemical liquid remains in the entire area within the processing liquid pipes 10 and 24, the lower processing liquid nozzle 14, and the upper processing liquid nozzle 25.
After stopping the introduction of the chemical liquid into the processing liquid pipes 10 and 24, the control unit 35 opens the valves 18V1 and 18V2. Thereby, introduction of nitrogen gas into the processing liquid pipes 10 and 24 is started from the fluid introduction parts 10a and 24a (step S5). Thereby, a gas extrusion process (S5, S6) is started.

By introducing nitrogen gas into the lower treatment liquid pipe 10, the chemical liquid remaining in the lower treatment liquid pipe 10 and the lower treatment liquid nozzle 14 is pushed out, and the chemical liquid is directed upward from the discharge port 14 a of the lower treatment liquid nozzle 14. Is discharged. The chemical liquid discharged from the lower processing liquid nozzle 14 flows on the lower surface of the rotating wafer W.
By introducing nitrogen gas into the upper treatment liquid pipe 24, the chemical liquid remaining in the upper treatment liquid pipe 24 and the upper treatment liquid nozzle 25 is pushed out, and the chemical liquid is directed downward from the discharge port 25 a of the upper treatment liquid nozzle 25. Is discharged. The chemical liquid discharged from the upper processing liquid nozzle 25 flows on the upper surface of the rotating wafer W or the upper surface of the spin base 5.

  Then, the chemical solution that has reached the peripheral edge of the wafer W receives a centrifugal force and scatters to the side, is received by the first guide portion 4a, and is then collected in the first collection tank 30. Other liquids such as a rinsing liquid are not mixed in the chemical liquid pushed out by nitrogen gas. Therefore, even if the chemical solution is recovered in the first recovery tank 30, no other liquid such as a rinse liquid is mixed into the first recovery tank 30.

Thus, the chemical solution collected in the first recovery tank 30 in step S3 is suitable for reuse, and after being sent to the chemical solution cabinet via the first drainage pipe 32, the chemical solution supply source 19 is again used. To be supplied. Some chemicals are expensive. By recovering and using such a chemical solution, the operation cost can be reduced.
When a predetermined time elapses after the valve 18V1 is opened, the control unit 35 closes the valve 18V1. Thereby, the introduction of nitrogen gas into the processing liquid pipe 10 is stopped (step S6, gas introduction stopping step). This predetermined time is a time set in advance so as to satisfy the condition that the introduction of the nitrogen gas is stopped in a state where the chemical liquid is not completely discharged from the processing liquid pipe 10 and the lower processing liquid nozzle 14. The predetermined time value is stored in the storage device of the control unit 35. The control unit 35 reads the predetermined time value before closing the valve 18V1.

  At this time, it is desirable that the amount of the chemical solution remaining in the processing liquid pipe 10 and the lower processing liquid nozzle 14 is small. For example, as shown in FIG. 4A, it is desirable that the chemical solution remains only in the vicinity (tip portion) of the discharge port 14 a of the pretreatment liquid nozzle 14. Further, in this case, as shown in FIG. 4B, the chemical liquid forms a first liquid reservoir DL1. The first liquid reservoir DL1 covers the entire cross-sectional area of the nozzle pipe (discharge port 14a) of the pretreatment liquid nozzle 14.

  Further, when a predetermined time elapses after 18V2 is opened, the control unit 35 closes the valve 18V2. Thereby, the introduction of nitrogen gas into the processing liquid pipe 24 is stopped (step S6, gas introduction stopping step). The predetermined time is a time set in advance so that the condition that the introduction of nitrogen gas stops in a state where the chemical liquid is not completely discharged from the processing liquid pipe 24 and the upper processing liquid nozzle 25 is satisfied. The predetermined time value is stored in the storage device of the control unit 35. The control unit 35 reads the predetermined time value before the valve 18V2 is closed.

  At this time, it is desirable that the amount of the chemical liquid remaining in the processing liquid pipe 24 and the lower processing liquid nozzle 14 is small. For example, as shown in FIG. 5A, it is desirable that the chemical liquid remains only in the vicinity (tip portion) of the discharge port 25 a of the upper processing liquid nozzle 25. Further, in this case, as shown in FIG. 5B, the chemical liquid forms a second liquid reservoir DL2. The second liquid reservoir DL2 covers the entire cross section of the nozzle pipe (discharge port 25a) of the upper process liquid nozzle 25.

In step S6, the closing timings of the valves 18V1 and 18V2 may be the same or different from each other.
When the introduction of nitrogen gas into the processing liquid pipes 10 and 24 is stopped, the gas extrusion process is completed.
For example, in Patent Document 1, in the process of discharging a chemical liquid or the like by introducing nitrogen gas from the processing liquid pipes 10 and 24, the lower processing liquid nozzle 14 and the upper processing liquid nozzle 25, the throughput of the chemical liquid is taken into consideration. The linear flow velocity is set to about 1 to 2 m / sec.

  However, in the embodiment of the present invention, as described above, the nitrogen gas introduction is precisely performed so that the introduction of the nitrogen gas is stopped in a state where the chemical liquid is not completely discharged from the lower treatment liquid pipe 10 and the lower treatment liquid nozzle 14. Need to control. Further, it is necessary to precisely control the introduction of nitrogen gas so that the introduction of nitrogen gas is stopped in a state where the chemical liquid is not completely discharged from the upper treatment liquid pipe 24 and the upper treatment liquid nozzle 25. Therefore, it is desirable to set the openings of the valves 18V1 and 18V2 in the gas extrusion steps (S5 and S6) so that the linear flow rate of nitrogen gas is lowered even if the throughput of the chemical solution extrusion is sacrificed to some extent.

  On the other hand, if the opening degree of the valves 18V1 and 18V2 is too small and the linear flow rate of nitrogen gas is too low, problems such as large fluctuations in the linear flow rate and a decrease in the throughput of the chemical solution extrusion may occur. Therefore, the balance of the above conditions is experimentally grasped, and appropriate opening degrees of the valves 18V1 and 18V2 in the gas extrusion process (S5, S6) are stored in the storage device of the control unit 35. The control unit 35 reads these opening degrees before the valves 18V1 and 18V2 are closed.

  In recent years, the performance of valves including opening / closing response accuracy has been improved. Therefore, the opening of the valves 18V1 and 18V2 in the gas extrusion step (S5, S6) is set low, and the time from the start of nitrogen gas introduction to the introduction stop is appropriately set, whereby the pretreatment liquid nozzle 14 and the upper treatment The gas extrusion step (S5, S6) can be performed so that the chemical liquid remains only in the vicinity (distal end portion) of the discharge ports 14a, 25a of the liquid nozzle 25. In this case, it is possible to avoid blowing nitrogen gas from the lower processing liquid nozzle 14 and the upper processing liquid nozzle 25 to the wafer W, and to remain in the processing liquid pipes 10 and 24, the lower processing liquid nozzle 14 and the upper processing liquid nozzle 25. The vast majority of the chemicals that have been removed can be discharged.

  Further, the liquid reservoirs DL1 and DL2 of the chemical liquid remaining in the vicinity of the discharge ports 14a and 25a of the lower process liquid nozzle 14 and the upper process liquid nozzle 25 respectively cover the entire cross section of the nozzle pipe (discharge ports 14a and 25a). Yes. Therefore, the liquid reservoirs DL1 and DL2 are so-called lids or liquids for preventing the nitrogen gas in the lower processing liquid nozzle 14 and the nitrogen gas in the upper processing liquid nozzle 25 from leaking out of the pipe. It will also serve as a seal. Therefore, the nitrogen gas is prevented from leaking out of the pipe until the rinse liquid is introduced into the processing liquid pipes 10 and 24 in the subsequent step S8. That is, the nitrogen gas is prevented from leaking to the wafer W.

Next, the control unit 35 controls the lower elevating mechanism 34 to lower the splash guard 4 from the collection position (see FIG. 1) toward the disposal position (see FIG. 2) (step S7).
While the splash guard 4 is lowered, the chemical liquid remains in the vicinity of the discharge ports 14a and 25a of the lower processing liquid nozzle 14 and the upper processing liquid nozzle 25, and this chemical liquid functions as a nitrogen gas lid. Fulfill. Therefore, it is possible to prevent the nitrogen gas existing in the lower processing liquid pipe 10 and the lower processing liquid nozzle 14 from leaking out of the lower processing liquid nozzle 14. Further, it is possible to prevent nitrogen gas existing in the upper treatment liquid pipe 24 and the upper treatment liquid nozzle 25 from leaking out of the upper treatment liquid nozzle 25.

  Next, the control unit 35 opens the valves 17V1 and 17V2. Thereby, the rinse liquid is introduced into the processing liquid pipes 10 and 24 from the fluid introducing portions 10a and 24a (step S8). At this time, the chemical solution and nitrogen gas remaining in the lower treatment liquid pipe 10 and the lower treatment liquid nozzle 14 are pushed out from the lower treatment liquid nozzle 14 in the form of being pushed out by the rinse liquid introduced into the lower treatment liquid pipe 10. Discharged in the direction. Specifically, the chemical solution and the nitrogen gas are discharged toward the lower surface of the wafer W. Following these chemicals and nitrogen gas, a rinsing liquid is discharged from the lower processing liquid nozzle 14 and supplied to the lower surface of the wafer W.

  At this time, the chemical liquid and the nitrogen gas are supplied to the wafer W together with the rinse liquid. However, since the chemical solution remaining in the pretreatment liquid nozzle 14 is relatively small and the chemical solution is diluted by the subsequent rinsing solution, there is almost no adverse effect on the wafer W due to the supply of the remaining chemical solution. Further, the pressure of the nitrogen gas remaining in the lower processing liquid pipe 10 and the lower processing liquid nozzle 14 is not high, so that the nitrogen gas is blown onto the wafer W to cause drying / contamination of the wafer W. Adverse effects can be virtually ignored.

  Further, the chemical solution and nitrogen gas remaining in the upper processing liquid pipe 24 and the upper processing liquid nozzle 25 are pushed out from the upper processing liquid nozzle 25 in a form of being pushed out by the rinse liquid introduced into the upper processing liquid pipe 24. Discharged. Specifically, the chemical liquid and the nitrogen gas are discharged toward the upper surface of the wafer W. Following these chemicals and nitrogen gas, the rinse liquid is discharged from the upper processing liquid nozzle 25 and supplied to the upper surface of the wafer W.

  At this time, the chemical liquid and the nitrogen gas are sprayed onto the wafer W together with the rinse liquid. However, since the chemical solution remaining in the upper process liquid nozzle 25 is relatively small, and the chemical solution is diluted by the subsequent rinsing solution, there is almost no adverse effect on the wafer W due to the supply of the remaining chemical solution. Further, the pressure of the nitrogen gas remaining in the upper processing liquid pipe 24 and the upper processing liquid nozzle 25 is not high, so that the nitrogen gas is blown onto the wafer W to cause drying / contamination of the wafer W. Adverse effects can be virtually ignored.

The rinsing liquid discharged from the pretreatment liquid nozzle 14 is supplied to the vicinity of the center of the lower surface of the wafer W held by the spin chuck 3, receives the centrifugal force due to the rotation of the wafer W, and moves the lower surface of the wafer W to the peripheral portion. Spread towards. Thereby, the chemical solution adhering to the lower surface of the wafer W is washed away by the rinse liquid (rinse liquid discharge process (treatment liquid discharge process)).
Further, the rinse liquid discharged from the upper processing liquid nozzle 25 is supplied to the vicinity of the center of the upper surface of the wafer W held by the spin chuck 3 and receives the centrifugal force generated by the rotation of the wafer W. Spreads toward the periphery. Thereby, the chemical solution adhering to the upper surface of the wafer W is washed away by the rinse liquid (rinse liquid discharge process (treatment liquid discharge process)).

The rinse liquid that has reached the peripheral edge of the wafer W receives a centrifugal force due to the rotation of the wafer W, scatters to the side, and is received by the second guide portion 4b. The rinse liquid that has landed on the second guide portion 4 b flows downward and is collected in the second collection tank 29. Since the rinse liquid collected in the second collection tank 29 contains a chemical solution and contaminants, the rinse liquid is discarded after being drained from the first drain pipe 31.
When a predetermined time has elapsed from the introduction of the rinsing liquid into the processing liquid pipes 10 and 24, the control unit 35 closes the valves 17V1 and 17V2. Thereby, the introduction of the rinsing liquid into the processing liquid pipes 10 and 24 is stopped (step S9). In this state, rinse remains in the entire area within the processing liquid pipes 10, 24, the lower processing liquid nozzle 14, and the upper processing liquid nozzle 25.

After stopping the introduction of the chemical liquid into the processing liquid pipes 10 and 24, the control unit 35 opens the valves 18V1 and 18V2. Thereby, introduction of nitrogen gas into the processing liquid pipes 10 and 24 is started from the fluid introduction parts 10a and 24a (step S10). Thereby, a gas extrusion process (S10, S11) is started.
By introducing nitrogen gas into the lower treatment liquid pipe 10, the rinsing liquid remaining in the lower treatment liquid pipe 10 and the lower treatment liquid nozzle 14 is pushed out and upward from the discharge port 14 a of the lower treatment liquid nozzle 14. The rinse liquid is discharged. The rinse discharged from the lower processing liquid nozzle 14 flows on the lower surface of the rotating wafer W.

By introducing nitrogen gas into the upper treatment liquid pipe 24, the chemical solution remaining in the upper treatment liquid pipe 24 and the upper treatment liquid nozzle 25 is pushed out and rinsed downward from the discharge port 25 a of the upper treatment liquid nozzle 25. The liquid is discharged. The chemical liquid discharged from the upper processing liquid nozzle 25 flows on the upper surface of the rotating wafer W or the upper surface of the spin base 5.
Then, the chemical solution that has reached the peripheral edge of the wafer W is subjected to centrifugal force and scattered to the side, and is received by the second guide portion 4b and then recovered to the second recovery tank 29.

  When a predetermined time elapses after the valve 18V2 is opened, the control unit 35 closes the valve 18V2. Thereby, the introduction of nitrogen gas into the processing liquid pipe 10 is stopped (step S11). This predetermined time is a time set in advance so that the condition that the introduction of the nitrogen gas stops in a state where the rinse liquid is not completely discharged from the processing liquid pipe 10 and the lower processing liquid nozzle 14 is satisfied. The predetermined time value is stored in the storage device of the control unit 35. The control unit 35 reads the predetermined time value before the valve 18V2 is closed.

  At this time, it is desirable that the amount of the rinsing liquid remaining in the processing liquid pipe 10 and the lower processing liquid nozzle 14 is small. For example, as in the case of step S10, it is desirable that the chemical liquid remains only in the vicinity (tip portion) of the discharge port 14a (see FIG. 4A) of the pretreatment liquid nozzle 14. In this case, the rinse liquid forms a liquid pool as in step S10. This liquid reservoir covers the entire cross-section of the nozzle pipe (discharge port 14a) of the pretreatment liquid nozzle 14.

  Further, when a predetermined time elapses after 18V2 is opened, the control unit 35 closes the valve 18V2. Thereby, the introduction of nitrogen gas into the processing liquid pipe 24 is stopped (step S11). The predetermined time is a time set in advance so that the condition that the introduction of nitrogen gas stops in a state where the chemical liquid is not completely discharged from the processing liquid pipe 24 and the upper processing liquid nozzle 25 is satisfied. The predetermined time value is stored in the storage device of the control unit 35. The control unit 35 reads the predetermined time value before the valve 18V2 is closed.

  At this time, it is desirable that the amount of the rinse liquid remaining in the processing liquid pipe 24 and the upper processing liquid nozzle 25 is small. For example, as in the case of step S6, it is desirable that the chemical liquid remains only in the vicinity (tip portion) of the discharge port 25a (see FIG. 5A) of the upper processing liquid nozzle 25. In this case, the rinse liquid forms a liquid pool as in step S6. This liquid pool covers the entire cross-sectional area of the nozzle pipe (discharge port 25a) of the processing liquid nozzle 25.

In step S11, the closing timings of the valves 18V1 and 18V2 may be the same or different from each other.
In the gas extrusion step (S10, S11), as in the case of the gas extrusion step (S5, S6), the opening degree of the valves 18V1, 18V2, the linear flow rate of nitrogen gas, It is desirable that it is low enough not to cause a problem such as reduction. Therefore, the balance of the above conditions is experimentally grasped, and appropriate opening degrees of the valves 18V1 and 18V2 in the gas extrusion process (S10, S11) are stored in the storage device of the control unit 35. The control unit 35 reads these opening degrees before the valves 18V1 and 18V2 are closed.

  In recent years, the performance of valves including opening / closing response accuracy has been improved. Therefore, the opening of the valves 18V1 and 18V2 in the gas extrusion step (S10, S11) is set low, and the time from the start of nitrogen gas introduction to the introduction stop is appropriately set, whereby the pretreatment liquid nozzle 14 and the upper treatment The gas extrusion step (S10, S11) can be performed so that the rinse liquid remains only in the vicinity (distal end portion) of the discharge ports 14a, 25a of the liquid nozzle 25. In this case, it is possible to avoid blowing nitrogen gas from the lower processing liquid nozzle 14 and the upper processing liquid nozzle 25 to the wafer W, and to remain in the processing liquid pipes 10 and 24, the lower processing liquid nozzle 14 and the upper processing liquid nozzle 25. The vast majority of the chemicals that have been removed can be discharged.

  As described above, in the case of the gas extrusion step (S5, S6) and the case of the gas extrusion step (S10, S11), the control unit 35 opens and closes the valves 18V1 and 18V2 and adjusts the opening degree by the same method. Do. However, the chemical solution and the rinse solution are different in physical properties such as viscosity. Therefore, in the case of the gas extrusion step (S5, S6) and the case of the gas extrusion step (S10, S11), the optimum opening degree and the time from the start of introduction of nitrogen gas to the stop of introduction are respectively optimum. Is set.

  Further, the rinsing liquid pool remaining in the vicinity of the discharge ports 14a and 25a of the lower process liquid nozzle 14 and the upper process liquid nozzle 25 covers the entire cross-section of the nozzle pipe (discharge ports 14a and 25a), respectively. Accordingly, the rinsing liquid pool is a so-called lid or liquid for preventing the nitrogen gas in the lower processing liquid nozzle 14 and the nitrogen gas in the upper processing liquid nozzle 25 from leaking out of the pipe. It will also serve as a seal. Therefore, the nitrogen gas is prevented from leaking out of the pipe until the rinse liquid is introduced into the processing liquid pipes 10 and 24 in the subsequent step S8. That is, the nitrogen gas is prevented from leaking to the wafer W.

Further, until the series of processing processes (S1 to S12) for one wafer W is completed and the series of processing processes (S1 to S12) for the next processed wafer W is started, the lower processing liquid nozzle 14 is used. It is possible to prevent contaminants from entering from the discharge port 14a and the discharge port 25a of the upper treatment liquid nozzle 25.
Note that it may be necessary to change the atmosphere in the chamber 2 to a nitrogen gas atmosphere following the rinsing liquid process from step S9 to step S12. In this case, in step S11, nitrogen gas is introduced until the chemical liquid is completely removed from the lower processing liquid nozzle 14 and the upper processing liquid nozzle 25, and then the atmosphere in the chamber 2 is sufficiently changed to a nitrogen gas atmosphere. The introduction of nitrogen gas may be continued until

  After the end of the rinsing process, the control unit 35 controls the lower rotation driving mechanism 8 to increase the rotation speed of the spin chuck 3. Further, the control unit 35 controls the lower rotation driving mechanism 23 to rotate the blocking plate 21 in the same direction as the spin chuck 3 at substantially the same rotational speed. Thereby, the wafer W is shaken off and dried. Thereafter, the control unit 35 controls the rotation driving mechanisms 8 and 23 to stop the rotation of the spin chuck 3 and the blocking plate 21.

Then, the control unit 35 controls the upper elevating mechanism 33 to raise the blocking plate 21 and the upper process liquid nozzle 25. Thereafter, the wafer W is unloaded from the chamber 2 by a robot hand (not shown) (step S12), and the chemical solution process and the rinse process for one wafer W are completed. Also for the next wafer W, the above-described S1 to S12 are similarly executed.
FIG. 6 is a schematic cross-sectional view of a main part of a substrate processing apparatus 100A according to another embodiment. In the substrate processing apparatus, the processing liquid pipe 124 connected to the processing liquid nozzle 125 branches to the processing liquid suction pipe 132. At the time of processing the wafer W, the valve 133A interposed in the processing liquid suction pipe 132 is closed with the processing liquid nozzle 125 disposed above the wafer W, and the valve interposed in the processing liquid pipe 125 is closed. 123A and 123B are all opened. As a result, the processing liquid flows through the processing liquid pipe 124 from the other end of the processing liquid nozzle 125 in the processing liquid pipe 124 toward the processing liquid nozzle 125, and is supplied to the wafer W from the end of the processing liquid nozzle 125. The

  After the processing, the processing liquid remains in the processing liquid nozzle 125 and the processing liquid pipe 124. These remaining processing liquids, particularly the processing liquid remaining inside the processing liquid nozzle 125, are moved below the processing liquid nozzle 125 by the action of gravity or the processing liquid residual pressure inside the processing liquid piping 124 from the end of the processing liquid nozzle 125. May cause a so-called dripping phenomenon. Such a dripping phenomenon causes contamination of the wafer W when the wafer W is present below the processing liquid nozzle 125. Even when there is no wafer W below the processing liquid nozzle 125, it is desirable to avoid the occurrence of such liquid dripping because it causes contamination of the apparatus.

  As a measure for avoiding dripping, there is a so-called suck back process (the suck back process is also described in Japanese Patent Laid-Open No. 5030767). As shown in FIG. 6, the valve 133 </ b> A and the valve 133 </ b> B on the processing liquid suction pipe 132 are opened with the valve 123 </ b> A interposed in the processing liquid pipe 125 closed. In this state, by operating the suction unit 134 such as a suction pump, the processing liquid remaining in the processing liquid nozzle 125 and the processing liquid pipe 124 is sucked through the processing liquid suction pipe 132 and is supplied to the suction unit 134. It is drained to a connected waste liquid facility (not shown) (suck back processing).

In some cases, the suction unit 134 is provided with a processing liquid recovery mechanism (not shown) to reuse the sucked processing liquid.
By such suckback processing, the above-mentioned dripping can be avoided. Further, the sucked processing liquid can be reused. However, the suck back process has a problem that the process takes a relatively long time. In addition, it may be difficult to stably operate the suction force by the suction unit 134 such as a suction pump.

FIG. 7 is a schematic cross-sectional view of a main part of a substrate processing apparatus 100B according to still another embodiment.
With reference to FIG. 7, another method (extrusion process by introducing nitrogen) for removing the remaining processing liquid from the processing liquid nozzle 125 and the processing liquid pipe 124 will be described.
In this alternative method, the multiple valve 101 is connected to the processing liquid pipe 124. A nitrogen pipe 111 and a processing liquid pipe 112 are connected to the multiple valve 101. The inside of the processing liquid pipe 124 communicates with the inside of the nitrogen pipe 111 and the inside of the processing liquid pipe 112 through the inside of the multiple valve 101. When the processing liquid remains in the processing liquid nozzle 125 and the processing liquid pipe 124, the processing liquid pipe 124 and the nitrogen pipe 111 are communicated with each other by switching the multiple valve 101, whereby the processing liquid pipe is passed through the nitrogen pipe 111. Nitrogen gas is introduced into 124. As a result, the processing liquid remaining in the processing liquid nozzle 125 and the processing liquid pipe 124 is discharged from the end of the processing liquid nozzle 125.

  While the nitrogen pipe 111 is closed by the multi-valve 101, the nitrogen gas filled in the nitrogen pipe 111 normally has a pressure exceeding the atmospheric pressure. Therefore, the nitrogen pipe 111 and the processing liquid pipe 124 are operated by operating the multi-valve. Is communicated with each other to introduce the nitrogen. When nitrogen gas is introduced and a predetermined time elapses, the operation of the multi-valve valve 101 shuts off the communication between the nitrogen pipe 111 and the processing liquid pipe 124. Thereby, the introduction of nitrogen gas is stopped, and the discharge of nitrogen gas from the supply port of the treatment liquid nozzle 125 is also stopped. The predetermined time is set to a time sufficient for completely removing the remaining processing liquid from the processing liquid nozzle 125 and the processing liquid pipe 124.

  However, when the processing liquid is completely removed from the processing liquid piping 124 and the processing liquid nozzle 125, only the nitrogen gas is discharged from the discharge port of the processing liquid nozzle 125, and the nitrogen gas discharged from the discharge port is the wafer W. It is sprayed directly on the main surface. Since the high-pressure nitrogen gas is directly blown onto the main surface of the wafer W, the main surface of the wafer W may be damaged. As a result, the processing quality of the wafer W may be degraded.

  As described above, according to this embodiment, after the discharge of the processing liquid (chemical liquid and rinsing liquid) from the discharge ports 14a and 25a of the processing liquid nozzles 14 and 25 to the wafer W is stopped, from the fluid introduction portions 10a and 24a. By introducing nitrogen gas into the processing liquid pipes 10 and 24, the processing liquid in the processing liquid pipes 10 and 24 and the processing liquid nozzles 14 and 25 are pushed outward (gas extrusion step (S5, S6)). S10, S11)). In this case, in a state where the processing liquid remains at the front ends of the processing liquid nozzles 14 and 25, in other words, the processing liquid is completely pushed out from the processing liquid pipes 10 and 24 and the processing liquid nozzles 14 and 25. Before the introduction of the nitrogen gas into the processing liquid pipes 10 and 24 is stopped. Therefore, it is possible to prevent the nitrogen gas introduced into the processing liquid pipes 10 and 24 from being directly blown onto the wafer W in the gas extrusion process.

Further, since the processing liquid remaining in the vicinity (tip portion) of the discharge ports 14a and 25a of the processing liquid nozzles 14 and 25 serves as a lid for the processing liquid nozzles 14 and 25, the discharge ports of the processing liquid nozzles 14 and 25 are used. Nitrogen gas can be prevented from leaking through 14a and 25a.
Further, according to this method, the introduction of the nitrogen gas into the processing liquid pipes 10 and 24 is stopped while the processing liquid remains at the tips of the processing liquid nozzles 14 and 25. Since the treatment liquid pipes 10 and 24 are significantly longer than the nozzle pipes of the treatment liquid nozzles 14 and 25, the volume of the treatment liquid pipes 10 and 24 is larger than the volume of the nozzle pipes of the treatment liquid nozzles 14 and 25. Is also big. Since the processing liquid remaining in the processing liquid pipes 10 and 24 and the processing liquid nozzles 14 and 25 other than the tips of the processing liquid nozzles 14 and 25 is removed, a gas extrusion process (S5, S6; S10, After the end of S11), no processing liquid exists in most of the processing liquid pipes 10, 24 and the processing liquid nozzles 14, 25. Thereby, the dripping of the process liquid from the discharge ports 14a and 25a of the process liquid nozzles 14 and 25 can be effectively suppressed.

As mentioned above, although one Embodiment of this invention was described, this invention can also be implemented with another form.
For example, in the above-described embodiment, the upper processing liquid nozzle 25 and the lower processing liquid nozzle 14 are fixed so as to be arranged on the center line of the wafer W. However, as the processing liquid nozzles 14 and 25, the upper surface of the wafer W is used. Alternatively, a scanning method in which the position moves along the lower surface may be employed. Even with such a nozzle, it is possible to adopt the configuration and method of the invention disclosed in the above-described embodiment.

  In the above-described embodiment, the flow rate of the nitrogen gas supplied to the processing liquid pipes 10 and 24 is adjusted by changing the opening degree of the valves 18V1 and 18V2, but the valves 18V1 and 18V2 are switched between open and closed. However, the opening may not be changed. In this case, an opening degree adjusting valve for adjusting the flow rate of the nitrogen gas supplied to the processing liquid pipes 10 and 24 by adjusting the opening degree of the nitrogen gas pipe 18 is provided separately from the valves 18V1 and 18V2. Also good.

  Further, in the above-described embodiment, the nitrogen gas in the gas extrusion step (S5, S6; S10, S11) is controlled by controlling the opening degree of the valves 18V1 and 18V2 and the time from the start of discharge of the treatment liquid to the stop of discharge. The amount of nitrogen gas introduced in the gas extrusion step (S5, S6; S10, S11) may be adjusted by controlling only the time from the start of discharge of the treatment liquid to the stop of discharge. .

  Further, as a method for introducing a predetermined amount of nitrogen gas, a configuration in which a pressurized gas tank 201 independent from a gas supply source of a supply source is provided on a piping system (for example, nitrogen gas piping) can be employed. In this case, as shown in FIG. 8, a pressurized gas tank 201 having a capacity smaller than the supply source of nitrogen gas or the like, that is, a capacity enough to store an amount of nitrogen gas necessary for the nitrogen gas introduction process is used. .

  Generally, precise control of the flow rate of nitrogen introduced from the nitrogen gas supply source 13 to the nitrogen gas pipe 18 is difficult, and in particular, when the flow rate is small, the introduction pressure and the introduction amount are precisely controlled. Is difficult. Therefore, a pressurized gas tank 201 as a kind of buffer tank that temporarily stores nitrogen gas or the like independent of the nitrogen gas supply source 13 is interposed in the nitrogen gas pipe 18. The pressurized gas tank 201 is interposed in the nitrogen gas pipe 18 so that both ends thereof are connected to the nitrogen gas pipe 18 via the tank valves 202, respectively.

  The control unit 35 switches introduction / stop of nitrogen gas into the processing liquid pipes 10 and 24 by opening and closing the valves 18V1 and 18V2. However, it is difficult to accurately control the amount of nitrogen gas introduced into the processing liquid pipes 10 and 24 only by opening / closing timing of the valves 18V1 and 18V2. Also, accurate timing control of opening and closing of the valves 18V1 and 18V2 has a limit due to the structural characteristics of the valve mechanism. Therefore, it may be difficult to precisely control the amount of nitrogen gas introduced into the processing liquid pipes 10 and 24 by opening and closing the valve valves 18V1 and 18V2.

On the other hand, in this modification, the internal pressure of the pressurized gas tank 201 is controlled, and the nitrogen gas inside the pressurized gas tank 201 is released in the nitrogen gas introduction process by opening and closing the tank valve 202, thereby providing a nitrogen gas supply source. The amount of nitrogen gas introduced into the processing liquid pipes 10 and 24 can be controlled with higher accuracy than when the nitrogen gas is directly released from the gas generator 13.
Further, in the gas extrusion step (S5, S6; S10, S11), after the start of the introduction of the nitrogen gas, the processing liquid remains in the tips of the processing liquid nozzles 14 and 25, and the inside of the processing liquid pipes 10 and 24 However, the timing of stopping the introduction of nitrogen gas is not limited to this, and the state in which the processing liquid remains in at least a part of the processing liquid pipes 10 and 24 (processing liquid piping) 10 and 24 and a state in which the processing liquid is not completely removed from the processing liquid nozzles 14 and 25).

  In the above-described embodiment, the case where the lower processing liquid nozzle 14 and the upper processing liquid nozzle 25 are provided has been described as an example. However, only one of the lower processing liquid nozzle 14 and the upper processing liquid nozzle 25 is provided. May be. When only the upper processing liquid nozzle 25 is provided, the spin chuck 3 is not limited to the sandwiching type, and for example, the wafer W is held in a horizontal posture by vacuum-sucking the back surface of the wafer W, and further the state A vacuum chucking type (vacuum chuck) that rotates the wafer W held by the spin chuck 3 by rotating around the vertical rotation axis may be employed.

Further, in the above-described embodiment, nitrogen gas is used as the gas for discharging the processing liquid from the processing liquid pipes 10 and 24 and the processing liquid nozzles 14 and 25. However, other gases such as clean air are used as this gas. An active gas may be used.
Further, a suction pipe (equivalent to the processing liquid suction pipe 132 in FIG. 6) may be branched and connected to the middle of the processing liquid pipes 10 and 24. In this case, a suction valve (equivalent to the suction valve 133A in FIG. 6) for interposing the suction pipe is interposed in the suction pipe, and a suction unit ( An equivalent to the suction unit 133 in FIG. 6 may be interposed. In the above-described embodiment, after the gas extrusion step (S5, S6; S10, S11) is finished, the processing liquid (chemical solution and rinsing liquid) remains at the tip of the processing liquid pipes 10, 24. In this case, the control unit 35 may control the suction valve and the suction unit so as to further perform a step of opening the suction valve for a short time in order to finely move the remaining processing liquid to the suction unit side. This reduces the possibility that the remaining processing liquid will drip from the front ends of the processing liquid nozzles 14 and 25 while retaining the advantage of the present invention in which the processing liquid remains at the front ends of the processing liquid pipes 10 and 24. it can.

  In the above-described embodiment, the semiconductor wafer W is taken up as a substrate to be processed. However, the present invention is not limited to the semiconductor wafer. For example, a glass substrate for a liquid crystal display device, a plasma display substrate, an FED substrate, an optical disk substrate, Other types of substrates such as a magnetic disk substrate, a magneto-optical disk substrate, a photomask substrate, a ceramic substrate, and a solar cell substrate may be processed.

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

1: Substrate processing apparatus 2: Chamber 3: Spin chuck 4: Splash guard 10: Lower processing liquid piping 10a: Fluid introducing part 14: Lower processing liquid nozzle 14a: Discharge port 16: Chemical liquid piping 16V1: Valve 16V2: Valve 17: Rinsing Liquid piping 17V1: Valve 17V2: Valve 18: Nitrogen gas piping 18V1: Valve 18V2: Valve 24: Upper processing liquid piping 24a: Fluid introduction part 25: Upper processing liquid nozzle 25a: Discharge port 100A: Substrate processing apparatus 100B: Substrate processing apparatus 201: Pressurized gas tank 202: Tank valve DL1: First liquid reservoir DL2: Second liquid reservoir W: Wafer

Claims (10)

A substrate processing method for performing processing using a processing liquid on a substrate to be processed,
A substrate holding step of holding the substrate in a horizontal posture by a substrate holding rotation mechanism;
By introducing the treatment liquid into the treatment liquid pipe from the fluid introduction part at the other end of the treatment liquid pipe provided at one end with the treatment liquid nozzle having the discharge opening at the tip, the treatment liquid is introduced into the substrate from the discharge opening. A treatment liquid discharge step for discharging toward the
A gas extrusion process for extruding the processing liquid in the processing liquid pipe and the processing liquid nozzle outward by introducing a gas from the fluid introduction part into the processing liquid pipe after stopping the processing liquid discharge process. When,
A gas introduction stopping step of stopping the introduction of the gas into the processing liquid pipe in a state where the processing liquid remains in the processing liquid pipe and / or the processing liquid nozzle after the introduction of the gas, Substrate processing method.   2. The substrate processing method according to claim 1, wherein in the gas introduction stop step, the introduction of the gas into the processing liquid pipe is stopped in a state where the processing liquid remains at the tip of the processing liquid nozzle.   The substrate processing method according to claim 1, further comprising a processing liquid recovery step of recovering the processing liquid excluded from the substrate from the recovery flow path in parallel with the gas extrusion step. The treatment liquid includes a chemical liquid,
The substrate processing method is as follows:
After the gas introduction stop step, the method further includes a rinse liquid discharge step of discharging the rinse liquid from the discharge port toward the substrate by introducing a rinse liquid into the treatment liquid pipe from the fluid introduction portion. The substrate processing method as described in any one of Claims 1-3. A substrate holding and rotating mechanism for rotating while holding the substrate in a horizontal position;
A processing liquid nozzle having a discharge port at the tip for discharging a processing liquid toward the substrate held by the substrate holding rotation mechanism;
A treatment liquid pipe provided with the treatment liquid nozzle at one end and a fluid introduction part for introducing the treatment liquid at the other end;
A treatment liquid supply pipe connected to the fluid introduction part and supplying a treatment liquid to the treatment liquid pipe;
A treatment liquid valve for opening and closing the treatment liquid pipe;
A gas pipe connected to the fluid introduction part and supplying gas to the treatment liquid pipe;
A gas valve for opening and closing the treatment liquid pipe;
A processing liquid discharge step of discharging the processing liquid from the discharge port toward the substrate by opening the processing liquid valve and introducing the processing liquid into the processing liquid pipe from the fluid introducing portion; and the processing liquid valve Is closed to stop the processing liquid discharge step, and then the gas valve is opened to introduce gas into the processing liquid pipe from the fluid introduction part, thereby processing in the processing liquid pipe and the processing liquid nozzle. A gas extruding step of extruding the liquid outward, and after starting the introduction of the gas, by opening the gas valve in a state where the processing liquid remains in the processing liquid piping and / or the processing liquid nozzle, A substrate processing apparatus comprising: a control unit that executes a gas introduction stop step for stopping introduction of gas into the processing liquid pipe.   The substrate processing apparatus according to claim 5, wherein the control unit stops the introduction of gas into the processing liquid pipe in a state where the processing liquid remains at the tip of the processing liquid nozzle.   The substrate processing apparatus according to claim 5, further comprising a pressurized gas tank capable of containing a gas and interposed in the gas pipe.   The substrate processing apparatus according to claim 5, further comprising a rinsing liquid pipe connected to the fluid introduction unit and supplying a rinsing liquid to the processing liquid pipe.   The substrate processing apparatus according to claim 5, further comprising a processing liquid recovery mechanism that guides the processing liquid pushed toward the substrate to a recovery flow path. An opening adjustment valve for adjusting the opening of the gas pipe;
The control unit stores a recipe,
The substrate processing apparatus according to claim 5, wherein the control unit opens and closes the gas valve and adjusts the opening of the opening adjustment valve based on the recipe.

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