Title:
CRYSTAL GROWTH DEVICE
Document Type and Number:
Japanese Patent JPS6311593
Kind Code:
A
Abstract:
PURPOSE:To improve the yield of crystals by providing an ultrasonic transmitter and a receiver at the lower part of a crucible shaft to obtain information regarding the position of a solid-liq. interface and ruggedness. CONSTITUTION:The ultrasonic transmitter and the receiver 2 are provided close to each other at the lower part of the shaft 1 supporting the crucible 3. An ultrasonic wave at several kHz to several MHz is generated from the transmitter side, transmitted to the solid-liq. interface 4 through the crucible 3, reflected, passed through the crucible 3 and the crucible shaft 1, and received by the receiver wherein the ultrasonic wave is transduced into an electric signal. The time of the transmitted pulse and that of the received pulse are observed through an oscilloscope 5, the distance between the lower part of the crucible shaft 1 and the solid-liq. interface 4 is measured while taking the sound velocity in the ceramic shaft 1 into account, and the position of the solid-liq. interface 4 is obtained. Besides, the transmitter and the receiver 2 are arranged in array, the ultrasonic wave is scanned in the plane of the solid-liq. interface 4, and the information regarding ruggedness on the solid-liq. interface 4 is obtained.
Inventors:
KAKIMOTO KOICHI
Application Number:
JP15555686A
Publication Date:
January 19, 1988
Filing Date:
July 01, 1986
Export Citation:
Assignee:
NEC CORP
International Classes:
C30B15/00; C30B15/22; H01L21/18; H01L21/208; (IPC1-7): C30B15/00; C30B15/22; H01L21/18
Attorney, Agent or Firm:
Uchihara Shin