FOREIGN MATTER INSPECTION DEVICE FOR SEMICONDUCTOR WAFER

PROBLEM TO BE SOLVED: To provide a foreign matter inspection device for semiconductor wafer which performs high-precision signal detection by variably controlling detection circuit characteristics according to a condition of a detection signal.SOLUTION: The foreign matter inspection device for semiconductor wafer includes a PMT 103 which detects reflected light; an amplifier circuit 301 which amplifies a signal detected by the PMT 103 and has response characteristics of the amplification controlled with a control signal; an A/D converter 302 which converts the signal amplified by the amplifier circuit 301 into a predetermined code and outputs the code; a control circuit 303 which generates the control signal based upon information on a semiconductor wafer 104 having correlation with the reflected light; and a data processing circuit which detects foreign matter on the semiconductor wafer 104 based upon the code output from the A/D converter 302.