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:
Jun. 26, 1984
Filed:
Sep. 02, 1981
Applicant:
Inventor:
Hans P Kleinknecht, Bergdietikon, CH;
Assignee:
RCA Corporation, New York, NY (US);
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
G01R / ;
U.S. Cl.
CPC ...
3241 / ; 324 715 ; 3241 / ;
Abstract
An apparatus and method for determining the doping profile of an epitaxial layer of a semiconductor as a function of conductivity (or resistivity) vs. distance (depth) includes modifying a d.c. generated current by a focused laser beam modulated at high frequencies in the order of 20 MHz, and directed in sequence on a point-by-point basis to the layer surface. Photocurrent variations from point-to-point effected by the laser beam striking the layer at each of the sequence of points are detected to provide a signal related to conductivity, (or, if desired, resistivity) of the layer material.