JP2000167440A - Liquid drip preventing method of nozzle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To surely prevent liquid drip from a nozzle regardless of whether air is incorporated or not in a liquid chemical and the quantity of the liquid chemical is large or small. SOLUTION: A sucking/discharging means 17 is connected with a auction nozzle 19 to the tip of a liquid chemical discharging nozzle 15, which is connected to a liquid chemical vessel 11 through an air control valve 16, and compressed air is jetted at a high speed from a high speed jetting nozzle part of the sucking/discharging means 17 by supplying the compressed air from a compressed air supply pump 22 to the sucking/discharging means 11 at the time of shutting out the liquid chemical to the nozzle 15 by the air control valve 16. As a result, the liquid chemical to be dropped from the tip of the nozzle 15 is sucked by reducing the pressure in a vacuum chamber of the sucking/ discharging means 17 to equal to or below the atmospheric pressure and the sucked liquid chemical is discharged through a diffuser of the sucking/ discharging means 17 to the atmosphere.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus for preventing dripping of a chemical solution from the nozzle tip after stopping the discharge of the chemical solution from the nozzle, and to a dripping prevention device for the nozzle.

[0002]

2. Description of the Related Art In a semiconductor manufacturing process, in wet etching and resist coating and development in a photolithography process, a method of discharging a chemical solution necessary for these processes from a nozzle is often adopted. Along with this, excess chemical liquid is inadvertently dropped from the tip of the nozzle after discharging the chemical liquid, which may adversely affect products in the process. Therefore, it is necessary to prevent the liquid from dripping from these nozzle tips. Conventionally, as such a method of preventing liquid dripping of a nozzle, a suck-back method of sucking a chemical solution at a nozzle tip by increasing a volume of a diaphragm after discharging a chemical solution is known.

A conventional nozzle dripping prevention device will be described with reference to FIGS. FIG. 3 is a configuration diagram of a chemical liquid passage for preventing dripping of a nozzle using a conventional suck back,
FIG. 4 is a cross-sectional view illustrating a conventional suck-back before dripping suction, and FIG. 5 is a cross-sectional view illustrating a conventional suck-back after dripping suction is completed. In FIG. 3, reference numeral 1 denotes a container for accommodating a chemical solution 2;
Is connected to an inert gas introducing pipe 3 for pressurizing the chemical solution 2 in the container with an inert gas such as nitrogen, and further connected to a chemical solution supply pipe 4 for leading the pressurized chemical solution out of the container 1. .
A nozzle 5 is connected to the tip of the chemical supply pipe 4, and an air control valve 6 for supplying and shutting off the pressurized chemical to the nozzle 5 is provided in the middle of the chemical supply pipe 4.
Further, in the chemical liquid supply pipe 4 between the air control valve 6 and the nozzle 5, a suck back 7 for preventing liquid dripping from the nozzle 5 is interposed.

As shown in FIGS. 4 and 5, the suck back 7 has a capacity of a housing 71 and a passage 74 communicating between an air control valve connecting port 72 and a nozzle connecting port 73 of the housing 71. A diaphragm 75 provided on the housing 71 so as to enlarge and reduce the pressure, a piston 76 provided slidably in the direction of expanding and contracting the diaphragm 75 in the housing 71, and the diaphragm 75 is extended by the piston 76. It is composed of a spring 77 biasing in the direction,
A port 79 for supplying compressed air is connected to a cylinder chamber 78 for moving the piston 76 in a direction in which the diaphragm 75 is compressed.

Next, the operation of the conventional nozzle liquid dripping prevention device configured as described above will be described. First, when the chemical liquid is discharged from the nozzle 5, compressed air is supplied from the port 79 to the cylinder chamber 78 to move the piston 76 in the direction of the arrow as shown in FIG. 4, thereby compressing the diaphragm 75. Passage 7 including 75
4 is kept in a reduced state. In this state, when the air control valve 6 is opened, the pressurized chemical solution 2 in the container 1 is supplied to the nozzle 5 through the chemical solution supply pipe 4, the air control valve 6, and the ports 72 and 73 of the suck back 7. The liquid medicine can be discharged.

On the other hand, in order to prevent liquid dripping from the nozzle 5, the supply of the chemical liquid to the nozzle 5 is shut off by closing the air control valve 6, and at the same time, the supply of compressed air to the port 79 of the suck back 7 is stopped. Stop and release the cylinder chamber 78 to the atmosphere. Along with this, the piston 76 moves in the direction of the arrow in FIG.
The diaphragm 75 is extended, and expands the volume A in the passage 74. As a result, the nozzle 5 communicating with this passage 74
The drug solution to be dripped in is sucked. As a result, dripping of the nozzle 5 can be prevented.

[0007]

However, as described above, in the conventional nozzle dripping prevention device, the diaphragm 75 is not used.
Since the amount of the chemical that can be sucked into the passage 74 by the extension of the liquid is constant, if air is mixed in the chemical, the amount of the chemical that can be sucked by the diaphragm 75 is changed by this air, and in the worst case, There is a possibility that the chemical liquid to be dropped from the nozzle 5 cannot be sufficiently sucked, causing dripping. In addition, since the diaphragm 75 is deteriorated (hardened) with the lapse of time, the amount of expansion and contraction of the diaphragm 75 decreases, and accordingly, the amount of chemical solution that can be sucked by the diaphragm also decreases. There was a problem that the chemical solution to be dropped could not be sufficiently sucked, causing dripping.

SUMMARY OF THE INVENTION The present invention has been made in view of the above points, and it is an object of the present invention to continuously discharge a chemical solution to be dropped from the nozzle tip to the atmosphere by vacuum suction and to discharge the chemical solution into the chemical solution. It is an object of the present invention to provide a nozzle dripping prevention device which can surely prevent dripping from a nozzle irrespective of the presence or absence of air mixing and the amount of a chemical to be dropped.

[0009]

In order to achieve the above object, the present invention provides a chemical solution supply source, a chemical solution discharge nozzle connected to the chemical solution supply source via a chemical solution supply pipe, and the chemical solution supply source. A device for supplying a chemical solution from a source to the nozzle, comprising a control valve for shutting off, and a device for preventing liquid dripping from a nozzle tip when shutting off the chemical solution to the nozzle by the control valve, wherein the control valve When the chemical solution is shut off to the nozzle, a suction / discharge means is provided for sucking a chemical solution to be dropped from the nozzle tip and discharging the sucked chemical solution.

In the present invention, when the supply of the chemical solution from the chemical solution supply source to the nozzle is interrupted, the suction / discharge means operates, and the vacuuming action generated by the high-speed injection of air causes
The chemical liquid to be dropped from the nozzle tip is continuously sucked, and simultaneously, the sucked chemical liquid is discharged to the atmosphere together with the jetting air. Therefore, according to the present invention, it is possible to reliably prevent dripping from the nozzle regardless of the presence or absence of mixing of air into the chemical and the amount of the chemical to be dropped.

[0011]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view of a nozzle drip prevention device according to an embodiment of the present invention. FIG. 1 is a configuration diagram showing an embodiment of a chemical liquid system provided with a nozzle dripping prevention device of the present invention, and FIG. 2 is a schematic sectional view showing an internal configuration of a suction / discharge unit in the present invention.

In FIG. 1, reference numeral 11 denotes a container for accommodating a chemical solution 12. The chemical solution container 11 is connected to an inert gas introduction pipe 13 for pressurizing the chemical solution 12 in the container with an inert gas such as nitrogen. Also, a chemical supply pipe 14 for connecting the pressurized chemical 12 to the outside of the container 11 is connected. A chemical solution discharge nozzle 15 is connected to the tip of the chemical solution supply pipe 14, and an air control valve 16 that supplies and shuts off the pressurized chemical solution to the nozzle 15 is provided in the middle of the chemical solution supply pipe 14. Have been.

Further, in FIG.
When the air control valve 16 shuts off the chemical solution to the nozzle 15, the chemical solution to be dropped from the tip of the nozzle 15 is sucked by a vacuuming action generated by high-speed injection of air, and the sucked chemical solution is injected at high speed. It is for discharging to the atmosphere together with air. This suction and discharge means 17
The suction port 171 (see FIG. 2) is connected to a suction nozzle 19 via a suction pipe 18, and this suction nozzle 19 is provided in contact with the tip of the chemical solution discharge nozzle 15. Also,
Compressed air supply port 172 of suction / discharge means 17 (see FIG. 2)
Is connected to a compressed air supply pump (compressed air supply source) 22 through an air control valve 20 and an air supply pipe 21.

As shown in FIG. 2, the suction / discharge means 17 includes a main body 173 made of a corrosion-resistant material such as Teflon.
And a vacuum chamber 174 formed in the main body 173 so as to communicate with the suction nozzle 19 via the suction pipe 18, and a small-diameter opening 175 </ b> A that is one end is formed in the main body 173 to communicate with the vacuum chamber 174. A diffuser 175 whose other end is a large-diameter opening 175B that is open to the atmosphere, and a diffuser 175 that projects into the vacuum chamber 174 and is formed in the main body 173 and has a compressed air supply port 17
High-speed injection nozzle unit 1 for high-speed injection of the compressed air supplied from 2 toward small-diameter opening 175A of diffuser 175
76.

Next, the operation of the nozzle dripping prevention device according to the present embodiment configured as described above will be described. First, when discharging the chemical solution from the nozzle 15, the air control valve 16 is opened. Thereby, the container 1
The pressurized chemical solution 12 in 1 is supplied to a nozzle 15 through a chemical solution supply pipe 14 and an air control valve 16, and the chemical solution can be discharged from the nozzle 15.

On the other hand, in order to prevent liquid dripping from the nozzle 15, as shown in FIG. 1, by closing the air control valve 16, the supply of the chemical liquid from the container 11 to the nozzle 15 is simultaneously shut off. The air control valve 20 is opened. Accordingly, the compressed air from the compressed air supply pump 22 is supplied to the air supply pipe 21 and the air control valve 20.
The compressed air is supplied from the compressed air supply port 172 of the suction / discharge unit 17 to the high-speed injection nozzle section 176 and the compressed air is supplied from the high-speed injection nozzle section 176 to the small-diameter opening 1 of the diffuser 175.
High-speed injection toward 75A. With the high-speed injection of the compressed air, the inside of the vacuum chamber 174 is depressurized to the atmospheric pressure or lower, and a chemical suction force is generated in the vacuum chamber 174, and
The liquid medicine to be dropped from the tip of the nozzle is sucked into the vacuum chamber 174 through the suction nozzle 19 and the suction pipe 18. This suction operation is continued while the compressed air is continuously injected from the high-speed injection nozzle portion 176 toward the small-diameter opening 175A of the diffuser 175. In addition, the high-speed injection nozzle unit 1
Compressed air injected at high speed from 76 is diffuser 175
When the chemical is drawn from the small-diameter opening 175A to the large-diameter opening 175B, the chemical solution sucked into the vacuum chamber 174 is discharged to the atmosphere through the diffuser 175 together with the high-speed jet air from the high-speed jet nozzle 176.

Therefore, according to the present embodiment, when the supply of the chemical solution from the container 11 to the nozzle 15 is interrupted, the suction / discharge means 17 is operated, and the vacuuming action generated by the high-speed injection of the compressed air is used. The liquid medicine to be dropped from the tip of the nozzle 15 can be continuously sucked and simultaneously discharged to the atmosphere through the diffuser 175 together with the air for ejecting the sucked chemical liquid. Liquid dripping from the nozzle 15 can be reliably prevented irrespective of the amount of the chemical liquid to be dropped.
Accordingly, it is possible to prevent an unnecessary chemical solution from being inadvertently dropped from the tip of the nozzle and adversely affecting the product in the process. Further, each component of the suction / discharge means 17 includes:
Since it does not include any movable parts such as a conventional suck-back, the suction / discharge means 17 can be used semi-permanently, and the main body 173 constituting the suction / discharge means 17 is molded from Teflon, so that the suction / discharge means 17 can be used. Can also be used for corrosive liquids.

The device for preventing liquid dripping of a nozzle according to the present invention can be applied not only to semiconductor manufacturing equipment but also to liquid crystal manufacturing equipment and the like. Further, the suction / discharge unit 17 of the present invention is not limited to the configuration shown in the above-described embodiment, but can be variously changed and modified without departing from the scope described in the claims.

[0019]

As described above, according to the nozzle liquid dripping prevention apparatus of the present invention, when the supply of the chemical solution from the chemical solution supply source to the nozzle is interrupted, the suction / discharge means operates and the high-speed injection of air is performed. The chemical action to be dropped from the tip of the nozzle can be continuously sucked by the vacuuming action generated at the nozzle, and at the same time, the sucked chemical can be discharged to the atmosphere together with the jetting air. Liquid dripping from the nozzle can be reliably prevented irrespective of the amount of the chemical solution to be attempted.

[Brief description of the drawings]

FIG. 1 is a configuration diagram showing an embodiment of a chemical solution passage provided with a device for preventing liquid dripping of a nozzle according to the present invention.

FIG. 2 is a schematic sectional view showing an internal configuration of a suction / discharge unit in the present invention.

FIG. 3 is a configuration diagram of a chemical liquid passage for preventing dripping of a nozzle using a conventional suck back.

FIG. 4 is a cross-sectional view showing a state before sucking a dripping of a conventional suck back.

FIG. 5 is a cross-sectional view showing a conventional state after sucking the liquid in a suck back.

[Explanation of symbols]

11 ... chemical solution container (chemical solution supply source), 12 ... chemical solution, 15
…… Nozzle for chemical liquid discharge, 16 …… Air control valve, 1
7 suction suction means 19 suction nozzle 20 air control valve 22 compressed air supply pump (compressed air supply source) 173 body 174 vacuum chamber 17
5: Diffuser, 176: High-speed injection nozzle section.

Claims (7)

[Claims] A chemical liquid supply source, a chemical liquid discharge nozzle connected to the chemical liquid supply source via a chemical liquid supply pipe, and a control valve for supplying and shutting off the chemical liquid from the chemical liquid supply source to the nozzle. A device for preventing liquid dripping from the nozzle tip when the control valve shuts off the chemical solution to the nozzle, wherein a chemical solution that is to be dropped from the nozzle tip when the control valve shuts off the chemical solution to the nozzle. An apparatus for preventing dripping of a nozzle, comprising suction and discharge means for sucking and discharging the sucked chemical solution. 2. The apparatus according to claim 1, wherein the suction of the chemical liquid by the suction / discharge means is performed by a vacuuming action generated by high-speed injection of air. 3. The suction / discharge means is formed in the main body so as to communicate with the main body and a tip of the nozzle,
A vacuum chamber for sucking a chemical solution to be dropped from the nozzle tip, a diffuser having one end formed in the main body in communication with the vacuum chamber and the other end being open to the atmosphere, and compressed air passing through the diffuser. A high-speed injection nozzle for high-speed injection from one end to the other end, wherein the high-speed injection of compressed air from the high-speed injection nozzle reduces the pressure in the vacuum chamber to an atmospheric pressure or less, and a chemical solution suction action into the vacuum chamber. 2. The apparatus according to claim 1, wherein the sucked chemical liquid is discharged to the atmosphere through the diffuser as it is generated and the compressed air is injected at a high speed.
A device for preventing dripping of the nozzle as described. 4. The apparatus according to claim 3, wherein the main body is formed of Teflon (registered trademark). 5. The apparatus according to claim 3, wherein the compressed air to the high-speed injection nozzle is supplied from a compressed air source. 6. The apparatus according to claim 3, wherein the supply and cutoff of the compressed air from the compressed air source to the high-speed injection nozzle section are performed by a control valve. 7. The apparatus according to claim 3, wherein the vacuum chamber communicates with a tip of the nozzle via a suction pipe and a suction nozzle.