JPS63110636A - Chemical treating system - Google Patents

Abstract

PURPOSE:To contrive the stabilization of a flow rate without making the air stagnate in a filter by a method wherein the deliverty of chemical is executed by a pump and a certain constant amount of the chemical is always sent back to a tank through the air vent of the filter during the actuation of the pump. CONSTITUTION:A pump 4 is connected to a buffer tank 1, a filter 2 provided with an air vent port 2a is connected to the output side of the pump 4 and a nozzle (a) is connected to the filter 2 through an air-operated valve 3. Moreover, the air vent port 2a of the filter 2 is connected to the buffer tank 1 through a return piping 10 and a needle valve 5 and a flowmeter 6 and installed midway of the return piping 10. A chemical (b) stored in the buffer tank 1 is pumped up by the pump 4, filtered by the filter 2 and sent to the nozzle (a). At the same time, the chemical passes through the needle valve 5 and the flowmeter 6 through the air vent port 2a of the filter 2 and sent back to the buffer tank 1 through the return piping 10. Thereby, bubbles generated in the piping and the pump 4 on the way are discharged through the air vent port 2a and the flow rate becomes a stable one.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a semiconductor wafer chemical processing apparatus that performs photoresist coating processing and current treatment on semiconductor wafers in semiconductor manufacturing processes, particularly photolithography processes. .

[Prior Art] Conventionally, this type of chemical processing apparatus has a pressurized buffer tank 1 connected to a filter 2 equipped with an air center boat 2a, as shown in FIG. 3, a plurality of nozzles are connected in parallel through 3, and pressurized nitrogen is sent into the buff 1 tank 1, and the gas pressure is used to forcefully send the chemical solution through the filter 2. Liquid is being sent. Also, open and close valve 9 of filter 2 to air 1
I've been doing Air 1 Friendship since ~2a.

[Problems to be Solved by the Invention] The liquid feeding system of the conventional chemical processing apparatus described above pressurizes a chemical liquid container with nitrogen, etc., feeds the liquid, filters it with a filter, and then drops the chemical liquid directly onto the semiconductor wafer from a nozzle. This method has the following disadvantages. That is, firstly, in order to pressurize the medicinal solution and send it, a considerable amount of pressurized gas is dissolved in the medicinal solution. For this reason, bubbles are likely to form in the chemical solution in the piping, and since these bubbles do not pass through the filter, they accumulate one after another on the primary side of the filter, resulting in an unstable flow rate. In the photolithography process, a chemical solution is dropped directly onto a semiconductor wafer, so it is important to control the flow rate to a constant level, and unstable flow rates pose a major problem.

Second, since the pressure is applied using compressible gas, there is a difference in the liquid feeding pressure between the start of liquid feeding and the steady liquid feeding, and it takes time for the liquid feeding flow rate to reach the steady liquid feeding state from the start of liquid feeding. decreases.

An object of the present invention is to provide a chemical liquid processing apparatus that delivers liquid at a stable flow rate.

[Differences between the invention and the prior art] In contrast to the conventional chemical processing apparatus described above, the present invention uses a pump to feed the chemical liquid, and a needle for adjusting the flow rate is provided in the piping system connecting the air 1 provided on the primary side of the filter. It is equipped with a valve and a flow meter for checking the flow rate, and by connecting this to a buffer tank, a certain amount of chemical solution is always returned after the air in the filter while the pump is operating, and this causes air to flow into the filter. It has the unique content of being able to prevent the current problem of liquid buildup and to deliver a stable flow rate of liquid.

[Means for Solving the Problems] The present invention provides a chemical solution processing device for supplying a chemical solution in a buffer tank to a processing section through a filter, in which a chemical solution supply pump is connected to the buffer tank, and the pump is connected to the buffer tank. A filter with an air port is provided in the liquid piping system, a return piping system is formed between the air rear port of the filter and the buffer tank, and a needle valve and a flow meter are provided in the return piping system. This is a chemical processing device characterized by the following.

[Example] Embodiments of the present invention will be described below with reference to the drawings.

(Example 1) FIG. 1 is a configuration diagram showing a first embodiment of the present invention.

In FIG. 1, a pump 4 is connected to a buffer tank 1 that stores a chemical solution, a filter 2 equipped with an air rear port 2a is connected to the output side of the pump 4, and an air operated valve 3 is connected to the filter 2. Connect the nozzle.

Further, the air rear port 2a of the filter 2 and the buffer tank 1 are connected by a return pipe 10, and a needle valve 5 and a flow meter 6 are installed in the middle of the return pipe 10.

The chemical solution introduced into the buffer tank 1 is pumped up by a pump 4, filtered by a filter 2, and sent to a nozzle. At the same time, the chemical solution is transferred to port 2 after the air of filter 2.
From a, it passes through a needle valve 5, a flow meter 6, and is returned to the buffer tank 1 via a return pipe 10.

When the chemical liquid is dripped from the nozzle, a part of the chemical liquid in the filter 2 returns to the buffer tank 1 from the primary side of the filter 2 without flowing to the nozzle. As a result, air bubbles generated in the intermediate piping or in the pump 4 are discharged from the air rear port 2a without being accumulated in the filter 2. Roughly speaking, the discharge pressure of the pump 4 is several orders of magnitude more stable than that of the pressure-feeding type, so it is possible to stably feed the meteor from the nozzle.

(Embodiment 2) FIG. 2 is a configuration diagram of Embodiment 2 of the present invention. This embodiment shows a developer piping system for a positive developing device used in a photolithography process, which is a semiconductor manufacturing process. The difference from the piping system shown in FIG. 1 is that a developer wetting tank 8 is provided between the buffer tank 1 and the pump 4, thereby controlling the developer temperature at a constant level.

In addition, pump systems are provided independently depending on the number of nozzles. 7 is a flow meter equipped with a needle valve. Therefore, since the developer is supplied to a plurality of nozzles using an independent pump system, a fixed amount of developer can be supplied to each nozzle, and there is an advantage that the chemical solution can be dropped stably.

[Effects of the Invention] As explained above, in the present invention, the chemical liquid is fed by a pump, and the chemical liquid at a constant level of 0 is returned to the tank after the filter air while the pump is in operation.
Is there air in the filter? 11 The flow can be stabilized, and the liquid is delivered by a pump, so
There is no discrepancy between the start of liquid feeding and the steady liquid feeding.
It is necessary to have the effect of being able to control the droplet value of a chemical liquid with high precision in a chemical liquid processing apparatus.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing a first embodiment of the present invention, FIG. 2 is a block diagram showing a second embodiment of the present invention, and FIG. 3 is a block diagram showing a conventional chemical processing apparatus. 1... Buffer tank, 2... Filter, 2a.
...Air 1 friendly port, 3...Air operated valve, 4...Pump, 5...Needle valve, 6...
...Flowmeter, 7...Flowmeter with needle valve, 8...
・Temperature control tank, 10...Return piping

Claims (1)

[Claims] (1) In a chemical processing device that supplies chemical liquid in a buffer tank to a processing section through a filter, a chemical liquid feeding pump is connected to the buffer tank, and an air vent port is provided in the liquid feeding piping system of the pump. 1. A chemical liquid processing device comprising: a filter; a return piping system formed between an air vent port of the filter and a buffer tank; and a needle valve and a flow meter provided on the return piping system.