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:
Mar. 13, 2007
Filed:
Sep. 28, 2004
William H. Howland, Jr., Wexford, PA (US);
Brian R. Bobrzynski, Pittsburgh, PA (US);
William H. Howland, Jr., Wexford, PA (US);
Brian R. Bobrzynski, Pittsburgh, PA (US);
Solid State Measurements, Inc., Pittsburgh, PA (US);
Abstract
To determine a concentration of defects and/or impurities in a semiconductor wafer, a first value of current is caused to flow in the semiconductor wafer having a substrate of semiconducting material. The semiconductor wafer is exposed to a pulse of light whereupon electron-hole pairs generated in the semiconductor wafer in response to the light pulse cause the current to increase to a second value. After termination of the light pulse, the rate of change of the current from the second value toward the first value is determined. A concentration of defects and/or impurities in the semiconductor wafer is determined as a function of the rate of change.