The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Aug. 01, 1989
Filed:
Oct. 26, 1987
Furukawa Electric Co., Ltd., Tokyo, JP;
Abstract
A method and an apparatus for growing a crystal of a compound semiconductor, in which a heater, used to heat a boat for growing the semiconductor crystal, is disposed around an ampule containing the boat, and a melt of the compound semiconductor, which is prepared in the boat, is freezed gradually at a predetermined temperature gradient including the freezing point of the melt, from a crystal growth starting end of the boat to a crystal growth terminating end thereof, whereby a single crystal or a polycrystal is grown. At the start of crystal growth, a crystalline nucleus is formed by periodically changing the temperature of the crystal growth starting end of the boat, in descending and ascending modes, within a temperature range lower than the melting point of the compound semiconductor, after once lowering the temperature of the starting end to a level lower than the melting point by means of a heater block opposed to the starting end. The crystal is grown around the crystalline nucleus formed in this manner. Preferably, the temperature change at the crystal growth starting end is slower in the descendng mode than in the ascending mode. The method of the invention may be applied without regard to the use of a seed crystal.