SUBSTRATE DEFECT DETECTOR

PROBLEM TO BE SOLVED: To check the contact of a rotary brush with a substrate or a wafer without stopping rotating the brush in a further improved way than the conventional brush contact detector. SOLUTION: A substrate defect detector has a transmitter 5 containing an ultrasonic vibrator, and a receiver 6 containing an ultrasonic vibrator mounted with leaving a space on a substrate 4; the transmitter 5 and the receiver 6 are connected to an oscillator 8 and a receiver 9 of a controller 7, respectively; and a monitor circuit 10 detects the change of received signals amplified by the receiver 9. If a rotary brush 11 contacts the substrate 4 in this condition; the intensity of ultrasonic waves transferred to the receiver 6 changes, causing to change the received signals detected by the ultrasonic vibrator of the receiver 6, the receiver 9 amplifies the received signals, and the monitor circuit 10 detects the change of the received signals inputted thereto, thus simply detecting that the brush 11 contacts the substrate 4. COPYRIGHT: (C)2008,JPO&INPIT