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:
Oct. 12, 1999
Filed:
Dec. 15, 1997
Hitach Cabel, Ltd., Tokyo, JP;
Abstract
An epitaxial semiconductor crystal plate or wafer capable of attaining increased reliability with enhanced luminance, a manufacturing method thereof as well as a light-emitting diode (LED). It has been found that epitaxial wafers with enhanced illuminance and increased yield of manufacture can be fabricated by specifically arranging a double-heterostructure epitaxial wafer such that the interface between its p-type clad layer 2 and p-type GaAlAs active layer 3 and that between an n-type GaAlAs clad layer 4 and p-type GaAlAs active layer 3 measure 1.times.10.sup.17 cm.sup.-3 or less in oxygen concentration. Also, in order to cause the oxygen concentration near the p-type GaAlAs active layer 3 in layers of the epitaxial wafer to be less than or equal to 1.times.10.sup.17 cm.sup.-3, it may be preferable that a nondoped GaAs polycrystal for use as a preselected original material in liquid-phase epitaxial growth be less than or equal to 1.times.10.sup.16 cm.sup.-3 or thereabout.