Pump Unit for Supplying Chemical Liquids

Abstract

A pump unit for supplying chemical liquids capable of reducing the trapping of air bubbles and chemical liquids inside the chemical liquid passage of the unit while reducing the size by forming the pump and open / close valves in the vicinity of the pump into a single unit. The pump unit 10 is formed by integrally mounting a suction-side passage member 17 with which a suction-side shutoff valve 13 is assembled together and a discharge-side passage member 18 with which a discharge side shutoff valve 14 is assembled together on the pump 11 (pump housings 21, 22). Suction passages 17a and 21b and discharge passages 18a and 21c communicating with a pump chamber 25 are disposed on the same line L1.

Description

TECHNICAL FIELD [0001] The present invention relates to a pump unit for supplying chemical liquids that is suitable for applying a predetermined volume of a chemical liquid, such as a photoresist liquid, to individual semiconductor wafers in the chemical-using process of a semiconductor manufacturing device, for example. BACKGROUND ART [0002] In a chemical liquid supply system, in order to pump a chemical liquid such as a photoresist out of a bottle and apply a predetermined volume of this liquid to individual semiconductor wafers, a pump and various necessary open / close valves individually disposed in the vicinity of the pump are usually connected using tubes. However, in such a system configuration, each tube connection requires a coupling, and the space necessary for installing these tubes and couplings increases the size of the chemical liquid supply system. [0003] Furthermore, to apply a chemical liquid simultaneously to multiple semiconductor wafers, multiple processing chambe...

AI Technical Summary

Benefits of technology

[0007] An object of the present invention is to reduce the size of the pump unit by forming the pump and the individual open / close valves in the vicinity of the pump into a single unit and to provide a pump unit for supplying chemical liquids that can reduce the trapping of air bubbles and chemical liquid inside the chemical liquid passage of the unit.

Problems solved by technology

However, in such a system configuration, each tube connection requires a coupling, and the space necessary for installing these tubes and couplings increases the size of the chemical liquid supply system.

However, the spaces inside these processing chambers are too small to house all of the necessary items, such as the nozzles for discharging the chemical liquid into the processing chambers, the discharge-side open / close valves, the pump, and the suction-side open / close valves.

Consequently, the length of the tube downstream of the pump and the height from the pump to the nozzle (pump head) differ for the individual processing chambers, resulting in differing levels of pressure loss.

Such differences can cause the volume of chemical liquid discharged from the individual processing chambers to vary, making it difficult to ensure a uniform discharging volume among all of the processing chambers.

Since chemical liquids such as photoresists are expensive, it is important to minimize the volume of chemical liquid to be purged in the process of expelling the air bubbles.

However, in the pump unit in patent reference 1, there is a 90-degree difference between the chemical liquid introduction direction in the input port and the chemical liquid discharge direction in the output port, and moreover, there are complicated bends in the chemical liquid passage inside the pump unit from the input port to the output port.

That is, the fact that air bubbles become trapped in some areas inside the chemical liquid passage prevents them from being reliably expelled using a small purging volume, necessitating a problematically large purge volume.

The chemical liquid also becomes trapped in the same areas as the air bubbles, and extended exposure to the trapped air can problematically deteriorate.

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