KR20030025436A - A photoresist suppling system for semiconductor processing - Google Patents

Abstract

PURPOSE: A photoresist supply system for semiconductor fabrication is provided to prevent the backflow of photoresist residues to a buffer tank by automatizing a process for collecting the photoresist residues and a process for supplying photoresist. CONSTITUTION: A supply tank(100) is used for storing photoresist. A buffer tank(110) is connected with the supply tank(100). A pump(130) is used for performing a pumping operation to pump the photoresist stored in the buffer tank(110). An injection nozzle(150) is used for injecting the photoresist pumped by the pump(130). A collection tank(160) is used for collecting the photoresist residues when the photoresist of the supply tank(100) is used up. A drain valve(200) is installed between the buffer tank(110) and the collection tank(160) in order to perform operations for opening or shutting a flow path.

Description

A photoresist suppling system for semiconductor processing

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a photoresist supply system for semiconductor manufacturing, and more particularly, to a photoresist supply system for semiconductor manufacturing which enables the collection of waste photoresist more efficiently.

Generally, a large amount of photoresist is used in the semiconductor manufacturing process. A typical photolithography process is a photolithography process, in which photoresist is applied to a wafer surface using a spin coating apparatus, then the applied photoresist is baked and irradiated with ultraviolet rays. It is a process of forming a photo mask for forming a required semiconductor circuit pattern.

At this time, the photoresist used is slightly different in the composition according to the thickness and characteristics of the photomask to be formed. Therefore, the photoresist used in each unit process has to be supplied in a separate supply system because its composition and characteristics are different.

The conventional photoresist supply system is roughly composed of an external supply tank, a buffer tank in which the photoresist supplied from the external supply tank is stored, a pump for pumping the photoresist, and a nozzle for finally spraying the pumped photoresist onto the wafer.

When the photoresist stored in the external supply tank is completely consumed, pressurizing nitrogen to the external supply tank to open and close the collection tank for collecting the waste photoresist remaining on the buffer tank and the flow path and the flow path between the collection tank and the buffer tank. A drain valve is provided.

The collection tank is also connected with other photoresist supply systems. Therefore, all waste photoresist collected from other supply systems are collected and stored together.

On the other hand, as mentioned above, when the photoresist of the external supply tank is consumed, nitrogen is pressurized into the supply tank to collect the photoresist remaining in the flow path and the buffer tank, and the waste photoresist is collected only when the drain valve is turned on. It will be collected in a tank.

Therefore, the user should turn off the drain valve when maintaining the normal photoresist supply state, and turn on the drain valve when collecting the waste photoresist.

However, since the conventional drain valve is operated by manual operation, if the user fails to timely perform the on / off operation of the drain valve, that is, the normal photoresist supply operation is performed while the drain valve is turned on. In this case, the waste photoresist of the collection tank flows back to the buffer tank by the collection pressure of the photoresist of the other supply system collected by the collection tank or the pumping force of the pump.

As such, when the waste photoresist of the collection tank flows backward, the waste water may be mixed with the photoresist used in the existing process, causing a fatal loss in the process. Therefore, in order to prevent such a problem, it is necessary to monitor and monitor the operation state of the drain valve at all times, resulting in inconvenience in the work, and also for the above reasons, there is always a risk in the process.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and an object of the present invention is to automatically turn on at the time of collection of the waste photoresist, and to turn off automatically at the time of normal photoresist supply to prevent the backflow of the waste photoresist, To provide a photoresist supply system for semiconductor manufacturing having a drain valve to improve the efficiency of the bed.

1 is a block diagram showing a photoresist supply system for manufacturing a semiconductor according to the present invention.

2 is a partially cutaway perspective view illustrating a drain valve installed in a photoresist supply system for manufacturing a semiconductor according to the present invention.

Figure 3a is a view showing a pre-operational state of the drain valve installed in the photoresist supply system for semiconductor manufacturing according to the present invention.

Figure 3b is a view showing a state during operation of the drain valve installed in the photoresist supply system for manufacturing a semiconductor according to the present invention.

** Description of the symbols for the main parts of the drawings **

100 ... supply tank

110 ... buffer tank

130 ... pump

200 ... drain valve

220 ... inner tube

230 ... Appearance

A photoresist supply system for semiconductor manufacturing according to the present invention for achieving the above object is a supply tank in which the photoresist is stored; A buffer tank in communication with the supply tank; A pump for forcibly pumping the photoresist stored in the buffer tank; A spray nozzle for spraying the photoresist pumped by the pump; A collection tank in communication with the buffer tank to collect the waste photoresist remaining on the flow path when the photoresist stored in the supply tank is exhausted; A drain valve installed between the buffer tank and the collection tank to open a flow path when an external pressure is applied to the inside of the supply tank for collection of waste photoresist, and an open / closed ball mounted on a spring to turn off when the external pressure is released; It includes.

And preferably, the drain valve is formed so that one end is in communication with the buffer tank side, the other end is in communication with the collection tank side, and the inner diameter is formed in the body from the inlet side to the outlet side is larger The spring and the opening and closing ball is installed therein.

In addition, the body is preferably formed by the inner tube installed in the opening and closing the ball and the spring is formed in the flow path spaced apart from the exterior and the predetermined interval.

In addition, the inner tube is characterized in that the communication hole is formed on the outer peripheral surface to communicate with the flow path.

Hereinafter, one preferred embodiment according to the present invention will be described in detail with reference to the drawings.

In the photoresist supply system for manufacturing a semiconductor according to the present invention, two supply flow paths are implemented as a single system, wherein each supply flow path is a path for supplying the same kind of photoresist, and the configuration is the same. Therefore, in the description of the configuration, only one photoresist supply path will be described, and the description of these supply paths will be explained in the description of other working states.

Referring to the configuration of a single photoresist supply path as shown in Figure 1, first, the external coupling is possible, the supply tank 100 is stored there is a photoresist installed therein, and connected to the supply tank 100 The buffer tank 110, which serves as a buffer for supplying photoresist, is installed. And the flow passage selection valve 120 is coupled to the supply pipe 170 extending from the buffer tank 110 and the supply pipe 170 extending from another supply path is coupled together to selectively supply the photoresist. .

After the selection valve 120, a pump 130 for forcibly pumping the photoresist is installed, and a filter 140 for filtering the pumped photoresist from the pump 130 is mounted. After the filter 140, the nozzle 150 is finally mounted to supply the photoresist by injection.

On the other hand, the buffer tank 110 is connected to the collecting pipe 180 for collecting the waste photoresist in addition to the supply pipe 170. The collection pipe 180 is connected to a collection tank 160 to which waste photoresist is collected at an outlet thereof, and a drain valve 200 between the buffer tank 110 and the collection tank 160 of the collection pipe 160. ) Is installed.

This drain valve 200 has a cylindrical body 210, one end and the other end of which is screwed to the collection tank 160, as shown in Figure 2, the body 210 forms an outer shape, the inside The outer surface 230 which is expanded so that the inner diameter becomes wider from the inlet side to the outlet side on one surface thereof is formed in the outer surface 230, and the flow path 240 is spaced apart from the inner surface of the outer surface 230 by a predetermined interval. It is provided with an inner tube 220 to form.

In particular, the inner tube 220 has a communication hole 222 which is an outlet communicating with the flow path 240 to the side so that the inlet 221 is in communication with the inlet of the exterior 230. In addition, a plurality of ribs 250 are formed on the outside of the portion of the inner tube 220 where the outlet side of the inner tube 220 is connected to the ends of the outer tube 230 and the inner tube 220, so that the inner tube 220 is formed. The inside of the exterior 230 is fixedly supported.

And the inside of the inner tube 220 is supported by a spring 260 mounted in the inner tube 220, the opening and closing ball 270 is mounted so as to slide in the inner tube 220. The opening and closing ball 270 has a diameter larger than that of the inlet of the inner tube 220 described above to open and close the inlet 221 of the inner tube 220.

On the other hand, the elastic force of the spring 260 installed here is to have an elastic force of a size smaller than the nitrogen supply pressure provided into the supply tank 100. Accordingly, when nitrogen pressure is provided to the buffer tank 110 through the supply tank 100, the opening / closing ball 270 opens the inlet 221 of the inner tube 220, and otherwise, the inlet of the inner tube 220. (221) is blocked.

Hereinafter, an operation state of the photoresist supply system for manufacturing a semiconductor according to the present invention configured as described above will be described.

The photoresist supply system for semiconductor manufacturing according to the present invention collects the photoresist remaining in the buffer tank 110 and the other supply pipe 170 when both the normal photoresist supply operation and the photoresist of the supply tank 100 are exhausted. The actions are implemented separately.

First, the normal supply state is performed in a state where the drain valve 200 is closed in a state as shown in FIG. 3A. When one of the two photoresist supply paths is selected by the selection valve 120, the selected supply is selected. Pump 130 is operated to pump the photoresist from the path.

When the pump 130 is operated, the photoresist of the supply tank 100 is pumped by the pumping force of the pump 130 to flow into the buffer tank 110, and the photoresist introduced into the buffer tank 110 continues. After passing through the selection valve 120 and the pump 130 is filtered through the filter 140 is injected into the upper surface of the wafer through the nozzle 150.

On the other hand, when all the photoresist is consumed from the first selected supply path during this operation, the selector valve 120 switches its direction to the second supply path to supply the photoresist from the second supply path.

At this time, the first supply tank 100 should be coupled to the new supply tank again to enable continuous photoresist supply when all the photoresist of the second supply path is exhausted. For this purpose, a waste photoresist collection operation is first performed.

This waste photoresist collection operation first supplies nitrogen pressure to the supply tank 100. Then, a high pressure is provided to the inside of the supply tank 100, the buffer tank 110, and the supply pipe 170 between the buffer tank 110 and the supply tank 100 at the pressure of the supplied nitrogen pressure.

At this time, the drain valve 200 is opened as shown in FIG. 3B by the provided pressure. That is, when the supplied nitrogen pressure is higher than the predetermined size, the pressure overcomes the elastic force of the spring 260 installed in the drain valve 200 to operate the opening / closing ball 270 installed in the drain valve 200 to discharge the drain valve 200. Inner tube 220 and the exterior 230 of the) will be in communication with each other.

In other words, when the opening and closing ball 270 enters the inside of the inner tube 220 by contraction of the spring 260, the inlet 221 of the inner tube 220 communicating with the inlet of the exterior 230 opens. Accordingly, the distribution path 240 communicates with the inlet 221 of the inner tube 220 through the communication hole 222 formed on the outer circumferential surface of the inner tube 220. Therefore, the waste photoresist is introduced through the flow passage 240 of the drain valve 200, and the waste photoresist is collected to the collection tank 160 through the collection pipe 180.

Then, all of these collection operations are completed, the nitrogen pressure applied to the supply tank 100 is removed, and the opening and closing ball 270 is restored to the extension of the spring 260 again by the removed nitrogen pressure to the inner tube 220. The inlet 221 of the will be blocked.

Accordingly, the path between the buffer tank 110 and the collection tank 160 is blocked from each other. This closed state is always maintained during normal photoresist supply operation, thereby preventing the photoresist from flowing backward. do.

The photoresist supply system for manufacturing a semiconductor according to the present invention as described above is provided with a spring and opening and closing ball so that the drain valve is automatically turned on / off by an external pressure, such as nitrogen supplied to collect the waste photoresist, The above configuration and some other structures can be applied for their operation, but if it is basically implemented by installing the spring and opening and closing ball all should be considered to be included in the technical scope of the present invention.

The photoresist supply system for semiconductor manufacturing according to the present invention as described above is automatically turned on at the time of collection of the waste photoresist, and automatically turned off when the normal photoresist is supplied to prevent the waste photoresist from flowing back into the buffer tank. In addition, there is an effect that can improve the operational efficiency for supplying a photoresist.

Claims (4)

A supply tank in which photoresist is stored; A buffer tank in communication with the supply tank; A pump for forcibly pumping the photoresist stored in the buffer tank; A spray nozzle for spraying the photoresist pumped by the pump; A collection tank in communication with the buffer tank to collect the waste photoresist remaining on the flow path when the photoresist stored in the supply tank is exhausted; A drain valve installed between the buffer tank and the collection tank to open a flow path when an external pressure is applied to the inside of the supply tank for collection of waste photoresist, and an open / closed ball mounted on a spring to turn off when the external pressure is released; Photoresist supply system for semiconductor manufacturing comprising a. 2. The drain valve of claim 1, wherein the drain valve has a body having a flow passage in which one end is in communication with the buffer tank side and the other end is in communication with the collection tank side, and an inner diameter thereof is formed inside the body, and goes from the inlet side to the outlet side. The photoresist supply system for semiconductor manufacturing, characterized in that the spring and the opening and closing ball is formed so as to become large. 3. The photoresist supply system of claim 2, wherein the body is formed by an inner tube having an exterior and the exterior spaced from the exterior by a predetermined interval to form the flow passage, and the opening and closing ball and the spring are installed therein. The photoresist supply system of claim 3, wherein a communication hole is formed in an outer circumferential surface of the inner tube so as to communicate with the flow passage.