Patent ID: 7990529

Claim:
A foreign matter inspection apparatus for a semiconductor wafer comprising: a reflection light detector which irradiates a semiconductor wafer, which is an object to be inspected, with irradiation light and detects reflection light from the semiconductor wafer; an amplifier which amplifies a signal based on the reflection light detected by the reflection light detector and in which response characteristics of amplification are controlled by using a control signal including radius information of the semiconductor wafer having a correlation with the reflection light and a relation between a detection circuit gain and a frequency determined in accordance with a radius position of the semiconductor wafer; an A/D converter which converts the signal amplified by the amplifier into a predetermined code and outputs the code; a control circuit which generates the control signal based on information of the semiconductor wafer having a correlation with the reflection light; and a data processing circuit which detects a foreign matter on the semiconductor wafer based on the code output from the A/D converter.