| 摘要 |
PURPOSE:To easily and quickly judge whether a crystal is a single domain or a multi-domain one by a method wherein the crystal is irradiated with an ultrasonic wave and a quantity of transmission loss of the wave after propagating in the crystal is measured. CONSTITUTION:A specimen 1 is put in pure water in a water tank 4 to be dipped therein and a contact probe 5 is put closer to an end face 2 of the specimen 1. An ultrasonic wave of about 10-30MHz is emitted from a transmitter 6 via the contact probe 5 thereto and a part of the wave that returns to the end face 2 by being reflected from the other end face 3 is received by the contact probe 5. The signal is inputted to a microcomputer 10 via a receiver 7, a detector 8 and an A/D convertor. The computer 10 scans the contact probe in the X, Y directions via a stage driver and checks it on the other points. A ratio of a sound pressure of one round trip of the ultrasonic wave between the end faces 2, 3 to that of two round trips thereof is obtained to calculate a quantity of the transmission loss. Based on the quantity of the transmission loss, it is possible to confirm the existence of a multi-domain in a single crystal ingot or in a wafer and to judge whether it is in a single domain condition or not. |
