METHOD AND APPARATUS FOR DETECTING MECHANICAL DEFECT OF INGOT BLOCK MADE OF SEMICONDUCTOR MATERIAL

PROBLEM TO BE SOLVED: To provide a method and an apparatus for detecting a mechanical defect of an ingot block made of a semiconductor material, which are applicable to all kinds of semiconductor material and enable a semiconductor wafer having a void to be separated at an early stage. SOLUTION: A flat surface 6 of the ingot block 1 having the thickness of 1 cm to 100 cm is scanned by an ultrasonic head 2 coupled through a fluid coupling medium 3. The ultrasonic head 2 emits ultrasonic pulses 8 toward the flat surface 6 of the ingot block 1 at respective measurement points x, y, and records echoes of ultrasonic pulses emitted from the ingot block 1 temporally. An echo 9 from the flat surface 6, an echo 11 from a flat surface 7 opposite to the flat surface 6, and another echo 10 arising according to circumstances are detected, and positions xp, ypand zpof the mechanical defect 4 of the ingot block 1 are obtained from the another echo 10. COPYRIGHT: (C)2008,JPO&INPIT