Patent ID: 6463941
Filing Date: 2002-10-15
Classification: B08B,G05D,H01L,Y10S

Abstract:
A concentration control apparatus of a liquid chemical, comprising:(a) a liquid chemical supplier section for supplying a liquid chemical; said liquid chemical being a mixture of source liquids, (b) a wafer treater section for applying a specific treatment to a semiconductor wafer using the liquid chemical supplied from said liquid chemical supplying section; said wafer treating section being connected to said liquid chemical supplying section through a communication line; (c) a concentration detector located in said communication line for detecting the concentration and/or composition of said liquid chemical flowing through said communication line; said concentration detector outputting a data signal about said detected concentration and/or composition of said liquid chemical; and (d) a data processor section for processing said data signal outputted from said concentration detector to output control signals to said liquid chemical supplier section; wherein said concentration and/or composition of said liquid chemical supplied from said liquid chemical supplier section is/are controlled by said control signals outputted from said data processor section, a pump being provided for each source liquid, the source liquids being mixed prior to flowing through a single valve, each pump being controlled by a control signal of said control signals.