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. 08, 1995
Filed:
Aug. 30, 1993
Shin-Etsu Handotai Kabushiki Kaisha, Tokyo, JP;
Abstract
An irradiation light containing a light which wave length is not absorbed by the n-type clad layer, but is absorbed by the p-type active layer, is applied on the wafer for manufacturing light emitting elements with a double-hetero structure of a p-type clad layer, a p-type active layer and an n-type clad layer formed one after another on a semiconductor substrate. Defects are found by detecting the increased photoluminescent light due to generation of a conductivity-type inverted layer such as the n-type inverted layer. When the double-hetero structure is composed of a GaAlAs mixed crystal compound semiconductor, the irradiation light which contains a wavelength range of 600-650 nm is applied. When the defective area is an active layer deficient area, detection is conducted by using the reflection light from the surface of the semiconductor substrate.