Soup concentration controller of semiconductor processing appts.

Abstract

The control device keeps concentration of liquor invariable and surface of liquor at height needed. The device provides following measuring functions: function of measuring concentration of liquor; function of observing drifting quantity of concentration, after a period of waiting time of concentration feed back control system; function of calculating quantity of supplement of liquor; function of forecasting concentration; function of handling quantity of supplement of liquor; and function of controlling quantity of supplement of liquor. Based on the said functions above, quantity of supplement of liquor is supplied according to preset standard quantity of supplement.

Description

[technical field] [0001] The present invention relates to a semiconductor processing device chemical solution concentration control device for maintaining a chemical liquid level required for semiconductor processing while keeping the processing chemical liquid concentration constant in a semiconductor processing device. [Background technique] [0002] In semiconductor processing equipment such as a wet bench (ウエツトステ-シヨン) and the like, the concentration of the chemical solution changes and the amount of the chemical solution decreases due to the removal of the wafer from the processing tank and the evaporation of the chemical solution. Therefore, the liquid medicine should be replenished regularly to maintain the concentration and volume of the liquid medicine. [0003] Figure 5 It is a block diagram showing the chemical concentration control of conventional semiconductor processing equipment. Such as Figure 5 As shown, in order to maintain the concentration of the liquid...

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Problems solved by technology

[0007] Therefore if Figure 8 As shown, in the case of controlling the concentration of the liquid medicine within the standard concentration range, due to the influence of the waiting time m2, sometimes it may exceed the upper limit of the standard concentration range or be lower than the lower limit of the standard concentration range, so sometimes the concentration will deviate

Similarly, even if PID (proportional-integral-derivative) control is performed, there is concern that the concentration cannot be controlled with high precision due to the influence of the waiting time m2

Due to fluctuations in the concentration of the chemical solution, cleaning, etching and other processes are unstable, which may lead to a decrease in the yield of semiconductors

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