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. 11, 1992
Filed:
Jul. 15, 1991
Tateo Kusama, Tokyo, JP;
Kinio Iba, Tokyo, JP;
Semitex Co., Ltd., Tokyo, JP;
Abstract
A method and apparatus measure the lifetime of semiconductor materials having resistivity values within a predetermined measurement range. Carriers are produced within the semiconductor material responsive to incident energy. Microwave energy is radiated from a waveguide onto the semiconductor material to obtain reflected microwave energy. The equivalent distribution circuit characteristics of the waveguide are varied such that a variation of a magnitude of the reflective microwave energy relative to a resistivity of the semiconductor material is substantially linear within the predetemined measurement range. Plural stub tuners are provided within the waveguide to obtain the desired linear characteristics. The lifetime measurement is obtained in accordance with an attenuation of the produced carriers.