TWI645450B - Processing liquid supply device, processing liquid supply method, and recording medium - Google Patents

Abstract

The present invention aims to provide a technique for suppressing the generation of particles when the processing liquid stops after the resist liquid is discharged from the nozzle 7 through the resist liquid supply path 51. According to the present invention, when the resist liquid is cut off, the suction return valve 3 is adjusted from the sucked-back state to the prepared state, and before the resist liquid returns to circulation from the temporarily stopped state of the resist liquid, the pneumatic valve is closed for more than 200ms. 2. Therefore, rapid shut-off and stop of liquid discharge can be achieved without closing the pneumatic valve 2 abruptly, so that particles generated by closing the pneumatic valve 2 abruptly can be reduced. In addition, in other examples, the pneumatic valve 2 is closed from the opening degree of 100% to 20% to temporarily stop the resist solution, and then the pneumatic valve 2 is closed from the opening degree of 20% to 0% to stop the liquid discharge.

Description

Process liquid supply device, process liquid supply method, and recording medium

The present invention relates to the technical field of a processing liquid supply device that supplies a processing liquid to a subject through a processing liquid supply path and a nozzle.

The semiconductor manufacturing process includes a step of supplying a processing liquid from a nozzle to a substrate to perform liquid processing. For example, a resist solution or a chemical solution for forming an antireflection film, or a chemical solution for forming an insulating film may be applied to a resist pattern forming system. The coating film is formed by a spin coating method in which a chemical solution is discharged from a nozzle to a substrate, and the coating film is formed by rotating the substrate. The supply and interruption of the chemical solution is to drive the pump of the chemical solution supply path and open the valve to discharge a set amount of the chemical solution from the nozzle, and then stop the pump and close the valve to stop supplying the chemical solution.

On the other hand, due to the continuous refinement of design rules, the allowable size of particles attached to the substrate is becoming stricter and the performance of the particle inspection device is improved to detect, for example, particles of approximately 20 nm. Therefore, it is an important issue to reduce particles generated in the chemical solution supply path. The main source of dust generation of the chemical liquid supply path is a valve, and a large amount of dust is generated by a discharge valve such as a distribution valve that stops supplying the chemical liquid.

The reason is that, for example, if a droplet flow is generated after the diffusion of the resist solution, the liquid must be cut off quickly to prevent the film thickness distribution from being adversely affected. Therefore, the closing speed of the discharge valve must be increased to increase the impact at the time of closing. Strict testing of the opening and closing of a discharge valve made up of, for example, a pneumatic valve, confirms that the elongated fine particles may be caused by the material of the valve. Therefore, it is necessary to reduce the dust generation of the discharge valve.

In Patent Document 1, there is a description that the closing time of the on-off valve is set to 300 ms in order to prevent the liquid droplet from flowing, but it is impossible to achieve a rapid shut-off in practice for such a long time. In addition, since suction preparation and suction valve closing operations are performed simultaneously, the operation of the processing liquid in the processing liquid supply path is complicated, so from this point of view, it is not possible to achieve rapid shutoff.

[Prior technical literature] [Patent Literature]

[Patent Document 1] Japanese Patent Application Publication No. 2010-171295 (paragraphs 0041, 0043, and FIG. 6)

The present invention has been made in such a case, and an object thereof is to provide a technology capable of suppressing the generation of particles when the processing liquid stops after the processing liquid is discharged from the nozzle through the processing liquid supply path.

The present invention is a processing liquid supply device that supplies a processing liquid to a to-be-processed object through a processing liquid supply path and a nozzle through a liquid feeding mechanism, and is characterized by including: a switching valve provided in the processing liquid supply path; A channel adjusting section provided in the processing liquid supply path between the on-off valve and the nozzle, and changing a cross-sectional area of a portion of the processing liquid supply path to adjust a volume; and a control section for temporarily stopping the processing liquid from being discharged from the nozzle, A control signal is output to the aforementioned flow path adjusting section, so that the volume of a part of the processing liquid supply path is changed from the first volume to a second volume smaller than the first volume and greater than zero, and the volume of a part of the processing liquid supply path is adjusted to the second After the volume is reached, a control signal is output to the on-off valve before the processing liquid that has been discharged is stopped and the circulation is started, so that the processing liquid supply path is closed.

Another invention is a processing liquid supply device that supplies a processing liquid to a to-be-processed body through a processing liquid supply path and a nozzle through a liquid feeding mechanism, and is characterized by including: a switching valve provided in the processing liquid supply path; And a control unit for temporarily stopping the discharge of the processing liquid from the nozzle, outputting a control signal to the on-off valve, changing the volume of the processing liquid supply path from a first volume to a second volume smaller than the first volume and greater than zero, and stopping Before the discharged processing liquid starts to flow again, a control signal is output to the on-off valve to close the processing liquid supply path.

Still another invention is a processing liquid supply method, which supplies a processing liquid to a to-be-processed object through a processing liquid supply path and a nozzle through a liquid feeding mechanism, and is characterized by using: a switching valve provided in the processing liquid supply path. And a flow path adjusting section, which is provided in the processing liquid supply path between the on-off valve and the nozzle, and changes the cross-sectional area of a part of the processing liquid supply path to adjust the volume, and performs the following steps: the processing liquid is discharged from the nozzle and supplied To the object to be processed; then, in order to temporarily stop the processing liquid from being discharged from the nozzle, the volume of the processing liquid supply passage is adjusted from the first volume to a second volume smaller than the first volume and greater than zero by the aforementioned flow path adjusting section; After the volume of the processing liquid supply path is adjusted to a second volume, the processing liquid supply path is closed by the on-off valve before the processing liquid that has been discharged is stopped and the circulation is started.

Still another invention is a processing liquid supply method, which supplies a processing liquid to a to-be-processed object through a processing liquid supply path and a nozzle through a liquid feeding mechanism, and is characterized by performing the following steps: discharging the processing liquid from the nozzle and supplying it to the processing object Then, in order to temporarily stop the processing liquid from being ejected from the nozzle, the volume of the processing liquid supply path is adjusted from the first volume to a first volume smaller than the first volume and greater than zero by means of a switching valve provided in the foregoing processing liquid supply path. Two volumes; and closing the processing liquid supply path by the aforementioned on-off valve before the processing liquid that has been discharged is resumed.

The recording medium of the present invention records a computer program for a processing liquid supply device, and the processing liquid supply device supplies a processing liquid to a subject through a processing liquid supply path and a nozzle through a liquid feeding mechanism. The recording medium is characterized in that : The aforementioned computer program is compiled into a group of steps in order to implement the above-mentioned method for supplying a processing liquid.

The present invention is directed to temporarily shut off the liquid by narrowing the processing liquid supply passage even if the processing liquid supply path is not completely closed, in terms of the liquid breaking of the processing liquid. Therefore, the volume of the processing liquid supply path is adjusted from the first volume to a second volume smaller than the first volume and greater than zero by the flow path adjusting section. The on-off valve closes the processing liquid supply path. Therefore, even if the liquid is not shut off abruptly, rapid liquid cut-off and liquid discharge stop can be achieved. Therefore, particles generated by abruptly closing the on-off valve can be reduced.

1‧‧‧valve unit

2‧‧‧pneumatic valve

3‧‧‧ Suction valve

6‧‧‧ treatment liquid container

7‧‧‧ Nozzle

9‧‧‧ Control Department

10‧‧‧Cup bearing module

11‧‧‧Rotary Chuck

12‧‧‧rotation axis

13‧‧‧rotating mechanism

14‧‧‧First Stream

15‧‧‧Second stream

16‧‧‧ Third Stream

17‧‧‧ Coupling

18‧‧‧ coupling

20‧‧‧First case

21‧‧‧Valve Chamber

22‧‧‧Valve seat

23‧‧‧Valve body

24‧‧‧Drive Room

25‧‧‧ Stem

26‧‧‧Spring member

27‧‧‧Circular Department

28‧‧‧upper area

29‧‧‧ area below

30‧‧‧Second shell

31‧‧‧ Diaphragm Room

32‧‧‧ diaphragm

34‧‧‧Drive Room

35‧‧‧ Stem

36‧‧‧Spring member

37‧‧‧Circular Department

38‧‧‧upper area

39‧‧‧ area below

41‧‧‧air flow path

43‧‧‧supply valve

44‧‧‧Exhaust valve

45‧‧‧Electromagnetic relay circuit

46‧‧‧ Hole

51‧‧‧ resist supply channel

52‧‧‧Filter

54‧‧‧Flow adjustment department

55‧‧‧Gas supply channel

56‧‧‧ buffer tank

57‧‧‧Atmosphere Open Road

58‧‧‧On-off valve

59‧‧‧On-off valve

60‧‧‧On-off valve

61‧‧‧air flow path

63‧‧‧supply valve

64‧‧‧Exhaust valve

65‧‧‧ electromagnetic relay circuit

66‧‧‧ Hole

71‧‧‧block

72‧‧‧ resist introduction port

73‧‧‧ resist discharge port

91‧‧‧valve

92‧‧‧Valve seat

93‧‧‧Valve body

100‧‧‧ resist supply device

200‧‧‧On-off valve

201‧‧‧ Motor

202‧‧‧Motor shaft

t1‧‧‧time

t2‧‧‧time

t3‧‧‧time

t4‧‧‧time

t5‧‧‧time

t6‧‧‧time

t7‧‧‧time

t8‧‧‧time

LC‧‧‧ hour

P‧‧‧Pump

W‧‧‧ Wafer

[FIG. 1] An explanatory view showing a resist liquid supply path of a processing liquid supply device of the present invention.

[FIG. 2] A sectional view showing a valve unit of the processing liquid supply device of the present invention.

[Fig. 3] Fig. 3 is an explanatory diagram showing a valve opening and closing sequence of a conventional treatment liquid supply device.

[Fig. 4] (a), (b), and (c) are explanatory diagrams showing the principle of liquid-cutting using the water hammer phenomenon.

[Fig. 5] Fig. 5 is an explanatory diagram showing a valve opening / closing sequence of the processing liquid supply device of the present invention.

[FIG. 6] An explanatory view showing an operation of a valve unit.

[Fig. 7] An explanatory view showing an operation of a valve unit.

[Fig. 8] Fig. 8 is an explanatory diagram showing an operation of a valve unit.

[FIG. 9] A sectional view showing another example of a valve unit according to the embodiment of the present invention.

[FIG. 10] A sectional view showing still another example of the valve unit according to the embodiment of the present invention.

[FIG. 11] A sectional view showing a valve unit of a second embodiment.

Fig. 12 is a characteristic diagram showing the effect of the embodiment.

[First Embodiment]

FIG. 1 shows a schematic view of a resist coating apparatus according to an embodiment of the liquid processing apparatus of the present invention. The resist coating apparatus includes a resist liquid supply apparatus 100 and a cup holder module 10 for a processing liquid supply apparatus. The cup receiving module 10 is configured to receive the scattered semiconductor wafer (hereinafter referred to as "wafer") W from the substrate through the cup 90 and discharge it from the exhaust pipe 101, and has an adsorption wafer W The central part of the rear surface keeps the rotating chuck 11 horizontal. The rotating chuck 11 is connected to the rotating mechanism 13 through a vertically extending rotating shaft 12. The rotation mechanism 13 includes a rotation drive source such as a rotation motor (not shown), and is configured to rotate at a predetermined speed.

The resist liquid supply device 100 includes a processing liquid container 6 that forms a processing liquid supply source that stores a processing liquid, that is, a resist liquid having a viscosity of 1 cP to 10 cP at 25 ° C., and a nozzle 7 that discharges the resist liquid (processing liquid ) To the substrate to be processed, that is, the wafer W; and the resist liquid supply path 51 is a processing liquid flow path formed by a pipe connecting the processing liquid container 6 and the nozzle 7. The resist liquid supply path 51 is sequentially provided from the upstream side: a buffer tank 56 for temporarily storing the processing liquid from the processing liquid container 6; a filter 52 for filtering the resist liquid to remove foreign matter; The pump P of the liquid-feeding mechanism; the flow rate adjusting unit 54; and an operation valve (hereinafter referred to as a “pneumatic valve”) 2 and a suction return valve 3 as a supply switching valve for the processing liquid.

A gas supply path 55 connected to a supply source of an inert gas such as nitrogen (N ₂ ) gas is provided in the gas phase of the processing liquid container 6. In addition, an upper part of the buffer tank 56 is provided with an atmosphere open path 57 for allowing an inert gas, such as nitrogen (N ₂ ) gas, to be trapped in the upper portion of the buffer tank 56 to the atmosphere. In addition, 58 to 60 series on-off valves are shown in the figure.

The pneumatic valve 2 and the suction return valve 3 constitute two connected valves which are connected to each other. If the two-valve structure is referred to as a valve unit, as shown in FIG. 2, the valve unit 1 has a substantially rectangular parallelepiped block 71 made of, for example, a fluororesin, and one side of the block 71 is formed. A resist liquid introduction port 72 is provided for supplying the processing liquid, and a resist liquid discharge port 73 is formed on a side facing the side.

A first flow path 14 is formed in the block 71 and is connected to the resist introduction port 72 and extends horizontally and extends upward. In addition, a cylindrical valve chamber 21 is formed inside the block 71, and the first flow path 14 is opened at a peripheral portion of a bottom surface of the valve chamber 21. In the center of the bottom surface of the valve chamber 21, the second flow path 15 is opened, and a valve seat 22 is provided so as to surround the periphery of the opening of the second flow path 15. The valve seat 22 is assembled so that the width becomes smaller toward the upper end. A valve body 23 that opens and closes the valve seat 22 is disposed in the valve chamber 21.

A first case 20 is provided above the valve chamber 21 on the upper side of the block 71. The first housing 20 has a driving chamber 24, and a valve stem 25 having a lower end connected to the valve body 23 and lifting in the driving chamber 24 is provided in the driving chamber 24. In addition, a circular plate portion 27 is provided around the valve stem 25, and the circular plate portion 27 is connected to the inner peripheral wall of the driving chamber 24 and is air-tightly bounded The upper region 28 and the lower region 29 of the fixed driving chamber 24. A spring member 26 provided between the upper surface of the circular plate portion 27 and the top plate of the drive chamber 24 and constantly imparting potential energy pushes the valve stem 25 downward.

A region 29 below the drive chamber 24 is connected to an air flow path 41 for supplying and discharging pressurized air, and a hole 46 for discharging air in the upper region 28 to the outside is provided in the upper region 28. The air flow path 41 is connected to a supply valve 43 that sends pressurized air to the lower region 29 and a discharge valve 44 that discharges pressurized air from the lower region 29. The supply valve 43 and the discharge valve 44 are configured to be controlled by an electromagnetic relay circuit 45. For example, if the solenoid in the electromagnetic relay circuit 45 is energized and turned on, the supply valve 43 is in an "open" state, and the discharge valve 44 It is in the "off" state, and pressurized air is supplied from the air flow path 41 to the lower region 29. When pressurized air is supplied to the lower region 29 to increase the pressure, the valve stem 25 rises against the biasing force of the spring member 26 and separates the valve body 23 from the valve seat 22. In addition, if the solenoid is turned off and disconnected, the supply valve 43 is in the "off" state, the discharge valve 44 is in the "on" state, and the pressurized air in the lower region 29 is discharged from the air flow path 41. As a result, if the pressure in the lower region 29 decreases, the valve stem 25 is lowered by the urging force of the spring member 26, so that the valve body 23 is placed on the valve seat 22. In this example, the first housing 20, the valve chamber 21, the valve body 23, and the valve seat 22 correspond to the pneumatic valve 2.

Returning to the second flow path 15, the other end of the second flow path 15 is connected to the diaphragm chamber 31. One end of the third flow path 16 is opened in the diaphragm chamber 31, and the other end side of the third flow path 16 is connected to the resist liquid discharge port 73. The top plate of the diaphragm chamber 31 is composed of the diaphragm 32 of a flexible member, and is configured such that if the diaphragm 32 is bent downward, the volume of the diaphragm chamber 31 decreases, and if the diaphragm 32 is bent upward, the volume of the diaphragm chamber 31 increases. The diaphragm chamber 31 can be said to constitute a part of the resist liquid supply path 51 in which the processing liquid flows in from the second flow path 15 and flows out to the third flow path 16. Therefore, by changing the volume of the diaphragm chamber 31, the cutoff of the resist supply path 51 can be adjusted. When the diaphragm 32 is bent to the lowermost side, the volume of the resist liquid supply path 51 is the smallest, and when the diaphragm 32 is bent to the uppermost side, the volume of the resist liquid supply path 51 is the largest. In addition, the diaphragm 32 is also provided so that the cross-sectional area of the resist liquid supply path 51 does not become zero when it is bent to the lowermost side.

A second case 30 is disposed above the diaphragm chamber 31 on the upper side of the block 71 so that the diaphragm 32 is bent upward and downward. The second housing 30 has a driving chamber 34, and the driving chamber 34 is provided with a valve stem 35 connected to the upper surface side of the central portion of the diaphragm 32 and lifting in the driving chamber 34. In addition, a circular plate portion 37 is provided around the valve stem 35, and the circular plate portion 37 is connected to the inner peripheral wall of the driving chamber 34 and hermetically defines an upper region 38 and a lower region 39 of the driving chamber 34. A spring member 36 provided between the bottom surface of the drive chamber 34 and the lower surface of the circular plate portion 37 and constantly imparting potential energy pushes the valve stem 35 toward the upper side.

The upper region 38 of the circular plate portion 37 of the driving chamber 34 is connected to the air flow path 61 for supplying and discharging pressurized air, and the lower region 39 is provided with a hole portion for exhausting the air in the lower region 39 to the outside. 66. The air flow path 61 is connected to a supply valve 63 that sends pressurized air to the upper region 38 and a discharge valve 64 that discharges pressurized air from the upper region 38. The supply valve 63 and the discharge valve 64 are configured to be controlled by an electromagnetic relay circuit 65. For example, if the solenoid in the electromagnetic relay circuit 65 is energized and turned on, the supply valve 63 is in an "open" state, and the discharge valve 64 It is in the "off" state, and pressurized air is supplied from the air flow path 61 to the upper region 38. When pressurized air is supplied to the upper region 38 to increase the pressure, the valve stem 35 is lowered against the biasing force of the spring member 36, and the diaphragm 32 is bent downward. In addition, if the solenoid is turned off and disconnected, the supply valve 63 is in the "off" state and the discharge valve 64 is in the "open" state, so that the pressurized air in the upper region 38 is discharged through the air flow path 61. As a result, the pressure in the upper region 38 decreases, and the valve stem 35 The energizing force of the member 36 rises, and the diaphragm 32 is bent upward. In this example, the second case 30, the diaphragm chamber 31, and the diaphragm 32 correspond to the suction check valve 3.

The resist liquid introduction port 72 and the resist liquid discharge port 73 in the valve unit 1 are connected to the resist liquid supply path 51 through the coupling members 17 and 18, respectively.

Referring to FIG. 1 again, the resist supply device 100 is provided with a control unit 9 composed of, for example, a computer. The control unit 9 has a program storage unit. The program storage unit stores a program that is programmed to switch the electromagnetic relay circuits 45 and 65 shown in FIG. 2, the flow rate adjustment unit 54, and the pump P to transmit a resist solution in accordance with the sequence described later. The program is stored and installed in the control section 9 through a recording medium such as a floppy disk, an optical disk, a hard disk, an MO (Optical Disk), a memory card, and the like.

The effect of the above embodiment will be described below. The wafer W as a substrate is transferred to the rotating chuck 11 in the cup holder module 10 by a transfer arm (not shown), and the wafer W is rotated by a predetermined number of rotations, and is ejected by the nozzle 7 at a preset ejection amount as The resist of the processing liquid reaches the center of the wafer W. The discharge of the resist liquid is to open the pneumatic valve 2 and operate the pump P to move the resist liquid in the buffer tank 56 sent from the processing liquid container 6 to the downstream side through the resist liquid supply path 51. Therefore, the resist liquid is discharged from the nozzle 7 at a flow rate set by, for example, the flow rate adjustment unit 54. Next, after a predetermined amount of the resist solution is discharged, the operation of the pump P is stopped and the discharge of the resist solution is stopped by the operations of the suction valve 3 and the pneumatic valve 2.

Here, before stopping the discharge of the resist liquid in this embodiment, that is, before the liquid is cut off from the nozzle 7, a case where the liquid is cut off by the closing operation of the pneumatic valve 2 as a comparative example is used as a comparative example. Figures 3 and 4 are explained on the one hand. Figure 3 shows the discharge and stop of the resist solution, the on and off of the solenoid (the example in Figure 3 In the figure, the time charts of the solenoids of the pneumatic valve 2 and the switches of the pneumatic valve 2 and the suction valve 3 are shown. First, the operation of discharging the resist solution is explained. At time t1, the electromagnetic relay circuit 45 for turning on and off the pneumatic valve 2 is turned on according to a signal from the control unit 9 (powered on the solenoid), so that the pneumatic valve 2 starts to open. And it becomes fully open at time t2. The resist liquid is gradually discharged while increasing the discharge flow rate of the nozzle 7 as the opening degree of the pneumatic valve 2 is increased, and is discharged at a set flow rate at time t2.

On the other hand, before the time t1, the suction check valve 3 is in a sucking state with a large opening degree, and at the time t1, the opening degree becomes small and is maintained at a predetermined small opening degree, that is, in a ready state. In addition, for the convenience of description, in the following description, in order to simplify the explanation of the opening degree of the suction valve, the terms "suction state" and "ready state" are used.

Then at time t3, the solenoid is disconnected according to a control signal from the control unit 9 (stops the solenoid from being energized), and the pneumatic valve 2 is fully closed at time t5 after time t3. That is, the pneumatic valve 2 closes abruptly and stops discharging the resist solution from the nozzle 7 at time t5. In addition, the opening degree of the suction valve 3 is increased from the ready state at time t3, and becomes the opening degree of the suction state at time t6. By increasing the opening degree of the suction-return valve 3, the resist liquid on the nozzle 7 side is attracted to the suction-return valve 3 side and the height of the liquid surface in the nozzle 7 is raised, so that the liquid droplet flow can be prevented.

Here, FIG. 4 shows a state in the resist supply path 51 when the pneumatic valve 2 is closed. By closing the pneumatic valve 2, the flow rate of the resist liquid on the upstream side of the pneumatic valve 2 decreases as the opening degree of the pneumatic valve 2 decreases as shown in FIG. 4 (a), and the flow rate becomes zero when fully closed. In contrast, on the downstream side of the pneumatic valve 2, even if the pneumatic valve 2 is fully closed, the resist liquid can flow to the nozzle 7 side due to inertial force. Therefore, as shown in FIG. 4 (b), the pneumatic valve 2 The vicinity of the spit outlet becomes a negative pressure state. Therefore, it is a phenomenon similar to the phenomenon when the negative pressure spring is stretched, and the area under negative pressure propagates toward the front end of the nozzle 7, reflects at the front end (open end) of the nozzle 7, and then pulls back. At this time, it is separated into the liquid lowered by the nozzle 7 and the liquid to be returned, and as a result, the liquid cut off at the front end of the nozzle 7 is formed. Then, the vibration of the resist in the flow direction of the resist supply path 51 is continuously attenuated, and finally the vibration is stopped. FIG. 4 (c) shows that the pressure at the front end of the nozzle 7 has elapsed over time, and after the negative pressure of the resist solution becomes the maximum, the liquid is cut off at the point when the negative pressure starts to decrease.

As can be seen from the above description, after the pneumatic valve 2 is closed, the resist liquid is in a negative pressure state, and it can be said that the liquid is cut off when it is pulled back later by the action of the negative pressure spring. Returning to the description of this embodiment, in this embodiment, each operation of the pneumatic valve 2 and the suction valve 3 is controlled by focusing on this phenomenon. FIG. 5 is a time chart including each switching state of the pneumatic valve 2 and the suction valve 3 of the present embodiment. When the supply of the resist is started, the state of the suction return valve 3 is different from that of the previous comparative example shown in FIG. 3, and is maintained in a suction return state with an opening degree larger than that of the preparation state. That is, although the solenoid of the electromagnetic relay circuit 45 on the pneumatic valve 2 side is turned on at time t1 and the pneumatic valve 2 is opened, the suction valve 3 becomes a suction state from time t1 and maintains the same after time t2 status. FIG. 6 shows the states of the pneumatic valve 2 and the suction return valve 3 from time t2 to t3.

Next, to stop the discharge of the resist solution in the nozzle 7, before the closing action of the pneumatic valve 2, the solenoid of the electromagnetic relay circuit 65 on the valve 3 side is cut off at time t3, so that the suction valve 3 is reduced from the suction state. The opening degree is in a ready state at time t4. FIG. 7 shows the state of the pneumatic valve 2 and the suction return valve 3 at this time. In other words, the state in which the opening degree of the suction check valve 3 is large does not become the state in which it is fully closed, but the state in which the degree of opening is slightly opened. As a result, as described above, the action of the negative pressure spring occurs on the downstream side of the suction and return valve 3 to cause a liquid cutoff, and the discharge of the resist liquid is stopped at time t5.

The reason for the action of the negative pressure spring is presumed as follows. Due to the action of the diaphragm 32 of the suction and return valve 3, the flow path is narrowed, that is, the volume of the flow path portion below the diaphragm 32 is reduced, and the diaphragm 32 is pressed into the resist solution. As a result, the flow rate of the resist solution on the downstream side becomes faster. The flow path becomes narrower, and the flow rate of the resist liquid on the upstream side of the suction return valve 3 becomes slower. On the other hand, the resist liquid on the downstream side can be kept flowing by inertial force. Therefore, a negative pressure is generated on the downstream side of the suction return valve 3 and vibration of the resist liquid is generated as described above. Therefore, after the suction return valve 3 is prepared, it is considered that a liquid cutoff occurs after a short period of time. In this example, the suck-back state corresponds to the first state, and the ready state corresponds to the second state.

If the time for the suction return valve 3 to change from the suction-back state to the ready state, that is, the time from the opening degree when the resist solution is ejected to the small opening degree used to generate the liquid cutoff is very long, the liquid cutoff will be unstable, so it should be For example, less than 100ms. The lower limit of the time does not need to be particularly limited technically, and can be determined according to the performance of the suction and return valve 3 used.

The capacity change rate of the suction valve 3 from the suction state to the preparation state [{(volume during suction-capacity during preparation) / capacity during suction}} × 100%], that is, by the action of the diaphragm 32 The capacity change interval, that is, the capacity change rate of the flow path portion between the diaphragm 32 and the projection area of the diaphragm 32 is preferably 5 to 30% or more.

Please refer to FIG. 5 again, although the liquid is cut off at time t5, since the pneumatic valve 2 is not closed, the resist solution starts to flow in this state (resist solution recirculation). Therefore, for example, at time t4 when the suction and return valve 3 is in a prepared state, the solenoid of the electromagnetic relay circuit 45 used to operate the pneumatic valve 2 is opened according to the control signal of the control unit 9, and the pneumatic valve 2 is closed. FIG. 8 shows the state of the pneumatic valve 2 and the suction valve 3 at time t7 when the pneumatic valve 2 is closed.

The closing operation of the pneumatic valve 2 is performed by discharging the pressurized air in the area 29 below the drive chamber 24. For example, by adjusting the conductivity of the air flow path 41 on the discharge side provided with the discharge valve 44, the air can be controlled. The discharge speed is the closing speed of the valve body 23. When the liquid cut depends on the sequence of the comparative example shown in FIG. 3 of the pneumatic valve 2, the time required for the pneumatic valve 2 to close is set to about 50ms. If the speed is slower than this, the liquid cut will be unstable. If the interruption of the liquid is unstable, after the resist is diffused by the centrifugal force on the wafer W, the liquid droplets flow and stretch on the surface, so there is a fear that the film thickness distribution pattern deviates from the predetermined pattern.

In contrast, in this embodiment, since the liquid is cut off by the suction and return valve 3, the closing operation of the pneumatic valve 2 may be performed within a period of time after the liquid is cut off and before the liquid flow is restarted. Therefore, the closing operation of the pneumatic valve 2 can be performed gently. The pneumatic valve 2 can be closed for a time longer than 200 ms, for example, 250 ms.

The time when the pneumatic valve 2 starts to close may be a time when the closing operation of the pneumatic valve 2 is performed using a time longer than 200ms, and the liquid flow does not restart after the liquid is cut off by the action of the suction valve 3. Therefore, the suction check valve 3 is not limited to the time when the pneumatic valve 2 starts to close at the time t4 when it is in the ready state, and the time at which the air valve 2 starts the closing operation may be after the time t4 when the suction valve 3 is in the ready state.

In the case where the closing operation of the pneumatic valve 2 is started before the time t4 at which the suction valve 3 becomes in a ready state, since the operation of the suction valve 3 and the operation of the pneumatic valve 2 overlap, 2 in the resist supply path 51 Volume changes occur at the same time. Therefore, the operation of the liquid in the resist liquid supply path 51 is complicated, and there is a possibility that the amount of liquid cutoff (the amount of liquid flowing from the nozzle 7 after the suction return valve 3 becomes ready) may increase. On the other hand, by starting the closing operation of the pneumatic valve 2 after the time t4 when the suction valve 3 is in a ready state, the volume change caused by the suction valve 3 in a prepared state and the volume change caused by closing the pneumatic valve 2 can be Staggered moments happen. Therefore, it is possible to suppress the amount of liquid interruption when the liquid operation in the resist liquid supply path 51 is not complicated.

Please refer to FIG. 5 again, at time t7 when the pneumatic valve 2 is closed, the solenoid of the electromagnetic relay circuit 65 on the side of the suction valve 3 is turned on according to the control signal, so that the opening of the suction valve 3 to the suction state starts to increase, and at the moment t8 becomes a suck-back state and stops raising the liquid level at the front end of the nozzle 7. After the stretching of the resist solution is terminated, the wafer W is rotated at a rotation speed corresponding to the film thickness adjustment step and the drying step, and is transferred to the outside by the cup holder module 10 after a series of processes are completed.

In the above-mentioned embodiment, in regard to the stoppage of the resist liquid discharged from the nozzle 7, the focus is on the phenomenon that a negative pressure spring is generated by narrowing the supply path of the resist liquid even if it is not completely closed, thereby temporarily stopping the liquid. In this example, the suction valve 3 is switched from the suction state to the prepared state to cause the liquid to be cut off, so that the pneumatic valve 2 on the upstream side of the suction valve 3 is provided to prevent the resist liquid from restarting the liquid flow and stop the liquid completely. Function. Therefore, it is not necessary to close the pneumatic valve 2 abruptly, so that generation of particles due to the abrupt closing of the pneumatic valve 2 can be reduced.

Hereinafter, another example of the valve unit 1 according to the embodiment of the present invention will be described. As shown in FIG. 9, the valve unit 1 may also be provided with a valve chamber 91 in the suction return valve 3 instead of the aforementioned diaphragm chamber 31. Further, a peripheral edge portion of the valve chamber 91 is connected to a downstream end of the second flow path 15, an upstream end of the third flow path 16 is opened at a center of a bottom surface of the valve chamber 91, and a valve seat 92 is provided around the opening portion. In addition, a valve body 93 is provided in the valve chamber 91 and is assembled to lower the valve stem 35 to place the valve body 93 on the valve seat 92.

In this case, if the opening degree of the valve body 93 is raised to the highest point, the opening degree is 100%, and when the valve body 93 is placed on the valve seat 92, the opening degree is 0%, and the percentage displayed by the height position of the valve body 93 is set. The value is the valve opening degree. The suction state of the first volume is, for example, 100% of the opening degree, and the preparation state of the second volume is, for example, 20% of the opening degree. and By closing the suction valve 3 from an opening degree of 100% to an opening degree of 20%, the volume above the opening of the third flow path 16 becomes smaller, and the flow velocity on the upstream side of the valve body 93 and the valve seat 92 becomes slower. On the downstream side of the valve body 93 and the valve seat 92, since it can flow to the nozzle 7 side by inertial force, a negative pressure can be formed near the opening of the third flow path 16 and the liquid can be cut off as described above to obtain the same effect. .

Another example of the valve unit 1 according to the embodiment of the present invention is shown in FIG. 10. The valve unit 1 of FIG. 10 is assembled in the structure shown in FIG. 2, and the vertical part on the pneumatic valve 2 side of the second flow path 15 is further dug down and then inclined obliquely up to the suction valve 3 side. Moreover, by making the bottom of the second flow path 15 higher than the structure of FIG. 2, the volume of the diaphragm chamber 31 can be reduced. With this structure, the change rate of the volume when the diaphragm 32 is bent downward, that is, the change rate of the cross-sectional area of the processing liquid flow path is larger, and the liquid can be cut off more reliably.

In the above embodiment, although the suction return valve 3 is provided with a liquid shut-off function, a volume of a part of the flow path may be provided in addition to the suction return valve 3 for raising the liquid level of the nozzle 7 after the liquid is cut. A flow path adjusting portion that changes from the first volume to a second volume smaller than the first volume. In this case, the flow path adjusting portion may be provided on either the upstream side or the downstream side of the suction return valve 3.

[Second Embodiment]

In the first embodiment, an example is shown in which the liquid cutoff and the resist liquid are blocked by separate valves. However, in the second embodiment, a valve in which the liquid cutoff and the resist liquid are blocked in common is shown. example. Although the structures of the valve chamber 21, the valve body 23, the valve stem 25, and the drive chamber 24 of the on-off valve 200 shown in FIG. 11 are approximately the same as those of the pneumatic valve 2 shown in FIG. 2 from a functional point of view, The driving source for the 25 action is different from the motor 201. The valve rod 25 is always provided with potential energy by the spring member 26 in the lower region 29, and is lowered together with the lowering of the motor shaft 202 of the motor 201. The restoring force of the component 26 increases. In such a valve, the flow rate rises by making the opening degree close to 100%, and the flow rate gradually decreases as the opening degree approaches 0%, and the supply of the resist solution is stopped when the opening degree becomes 0%. Therefore, from time t3 to time t4 shown in FIG. 5, the on-off valve 200 is closed from, for example, an opening degree of 100% to an opening degree of 2 to 10%.

If such an operation is performed, the volume on the lower side of the valve body 23 becomes drastically smaller, and the flow velocity on the downstream side of the valve body 23 becomes faster and the same as the phenomenon caused by the suction valve 3 of the first embodiment. The ground produces the effect of a negative pressure spring and similarly produces a fluid cut. Since the liquid flow may restart in this case, the motor shaft 202 may be lowered by the motor 201, and the opening degree of the on-off valve 200 is 0% before the liquid flow restarts, even if the on-off valve 200 is closed. In this case, the action of closing the on-off valve 200 can also be used to stop the liquid flow and then start the liquid flow, and then slowly open the opening degree from, for example, 2 to 10% to 0 for a period of more than 200ms. % Closing action.

In this example, although the opening degree of the on-off valve 200 is equivalent to the first volume when the opening degree is 100%, and the second volume is smaller than the first volume when the opening degree is 2 to 10%, it is equivalent to the first volume for generating a liquid cutoff. The openings of the volume and the second volume can be set to appropriate values by performing experiments in advance.

The treatment liquid used in the present invention is not limited to a resist liquid, but may also be a chemical liquid for an antireflection film, a chemical liquid containing a precursor substance of an insulating film, a diluent, pure water, etc. Process.

In addition, the liquid-feeding mechanism is not limited to the pump P, and may be, for example, a liquid-feeding mechanism that supplies gas to the gas phase of the air flow path 61 to apply pressure to the processing liquid and pressure-feeds the processing liquid.

[Confirmation test]

In order to verify the effect of the present invention, the following tests were performed. The test method is to sequentially arrange the pump, the valve unit 1 and the nozzle shown in FIG. 2 on the upstream side, and set a pressure gauge on the downstream side of the valve unit 1, and use a diluent as a liquid. Furthermore, in the case where the suction return valve 3 is closed abruptly as in the aforementioned comparative example (FIG. 3), and in the case where the suction return valve 3 is changed from the suction state to the prepared state as in the embodiment (FIG. 5), the pressure gauge is measured Time to detect pressure. The measurement results are shown in FIG. 12, the dotted line (1) corresponds to a comparative example, and the solid line (2) corresponds to an embodiment.

From this result, it can be seen that, in the same manner as the attenuation vibration of pressure generated in the comparative example, the attenuation vibration of pressure was formed in the embodiment. In addition, in the embodiment, a temporary liquid cut-off can be confirmed. Therefore, according to the present invention, the liquid can be shut off by changing the volume of a part of the flow path from large to small, so it can be confirmed that the aforementioned effects are obtained.

Claims (11)

A processing liquid supply device that supplies a processing liquid to a to-be-processed object through a processing liquid supply path and a nozzle through a liquid feeding mechanism, and is characterized in that it includes an on-off valve provided in the processing liquid supply path; a flow path adjustment section It is provided in the processing liquid supply path between the on-off valve and the nozzle to change the cross-sectional area of a part of the processing liquid supply path to adjust the volume; and a control unit for temporarily stopping the discharge of the processing liquid from the nozzle And outputting a control signal to the flow path adjusting section to change the volume of a portion of the processing liquid supply path from the first volume to a second volume smaller than the first volume and greater than zero, and adjust the volume of a portion of the processing liquid supply path After reaching the second volume, a control signal is output to the on-off valve, and the processing liquid supply path is closed before the processing liquid that has stopped being discharged is resumed. For example, the processing liquid supply device of the first patent application range, wherein the time required for the closing operation of the on-off valve is set to 200 ms or more. For example, the processing liquid supply device according to item 1 or 2 of the scope of patent application, wherein the time required for the volume adjusted by the flow path adjusting section to change from the first volume to a second volume smaller than the first volume and greater than zero is set to Less than 100ms. For example, the processing liquid supply device according to item 1 or 2 of the patent application scope, wherein the processing liquid flow path on the downstream side of the switching valve is provided with a suction return valve for raising the liquid level of the nozzle after stopping the discharge of the processing liquid. The suction return valve also serves as the flow path adjusting portion. For example, the processing liquid supply device of the scope of application for patents 1 or 2, wherein the viscosity of the processing liquid is 25. At C it is 1 cP to 10 cP. A processing liquid supply device that supplies a processing liquid to a to-be-processed body through a processing liquid supply path and a nozzle through a liquid feeding mechanism, and is characterized by including: an on-off valve provided in the processing liquid supply path; and a control section, In order to temporarily stop discharging the processing liquid from the nozzle, it outputs a control signal to the switching valve, changes the volume of the processing liquid supply path from a first volume to a second volume smaller than the first volume and greater than zero, and outputs to the switching valve. The control signal closes the supply path of the processing liquid before stopping the processing liquid from being discharged again. A liquid processing apparatus, comprising: a substrate holding section that holds a substrate of a processing object subjected to liquid processing by a processing liquid horizontally; and a cup holder module that is provided to surround the substrate holding section and make the inside thereof Exhaust; a processing liquid supply device such as any one of claims 1 to 6 of the scope of patent application; and a moving mechanism that moves the nozzle. A processing liquid supply method, which supplies a processing liquid to a to-be-processed object through a processing liquid supply path and a nozzle through a liquid feeding mechanism, and is characterized by using: an on-off valve provided in the processing liquid supply path; and a flow path An adjusting unit is provided in the processing liquid supply path between the on-off valve and the nozzle, and changes the cross-sectional area of a part of the processing liquid supply path to adjust the volume, and performs the following steps: the processing liquid is discharged from the nozzle and supplied to the object to be processed ; Then, in order to temporarily stop the processing liquid from being discharged from the nozzle, the volume of the processing liquid supply path is adjusted from the first volume to a second volume smaller than the first volume and greater than zero by the flow path adjusting section; and the processing liquid After the volume of the supply channel is adjusted to the second volume, the processing liquid supply channel is closed by the on-off valve before the processing liquid that has been discharged is resumed. For example, the method for supplying a processing liquid according to item 8 of the scope of patent application, wherein the step of closing the processing liquid supply path by the on-off valve is a step of closing the processing liquid supply path by a closing action of 200 ms or more. A processing liquid supply method that supplies a processing liquid to a processing object through a processing liquid supply path and a nozzle through a liquid feeding mechanism, and is characterized by performing the following steps: discharging the processing liquid from the nozzle and supplying the processing liquid to the processing object; and In order to temporarily stop the processing liquid from being discharged from the nozzle, the volume of the processing liquid supply path is adjusted from the first volume to a second volume smaller than the first volume and greater than zero by a switching valve provided in the processing liquid supply path; and The processing liquid supply path is closed by the on-off valve before the processing liquid that has been discharged is resumed. A recording medium that records a computer program for a processing liquid supply device that supplies a processing liquid to a subject through a processing liquid supply path and a nozzle through a liquid feeding mechanism. The recording medium is characterized in that : The computer program includes a group of steps for implementing a method for supplying a processing liquid as described in any one of claims 8 to 10 of the scope of patent application.