SUBSTRATE INSPECTING APPARATUS

摘要

PROBLEM TO BE SOLVED: To ensure a sufficiently large high sensitivity detection region without lowering detection sensitivity even if diffracted light and scattered light are intensively generated from a part having a TFT pattern provided thereto. SOLUTION: A laser 10 irradiates the surface of a substrate 20 with laser beam and a photodetector 14 receives the diffracted beam and scattered beam of the laser beam applied to the substrate 20. An integrating circuit 17 integrates the signal corresponding to one line of the photodetector 14 and a conversion table 18 outputs the value related to the intensity of the laser beam emitted from the laser on the basis of the integrated value. A PWN control and oscillation circuit 19 and a drive means 11 drive the laser 10 based on the value related to the intensity of laser beam to control the laser 10 so as to emit laser beam with a predetermined intensity from the laser 10.