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:
Jul. 11, 2006
Filed:
Sep. 22, 2004
Bradley J. Albers, Dallas, TX (US);
Thomas Craig Esry, Orlando, FL (US);
Daniel Charles Kerr, Orlando, FL (US);
Edward Paul Martin, Jr., Orlando, FL (US);
Oliver Desmond Patterson, Poughkeepsie, NY (US);
Bradley J. Albers, Dallas, TX (US);
Thomas Craig Esry, Orlando, FL (US);
Daniel Charles Kerr, Orlando, FL (US);
Edward Paul Martin, Jr., Orlando, FL (US);
Oliver Desmond Patterson, Poughkeepsie, NY (US);
Agere Systems, Inc., Allentown, PA (US);
Abstract
A method and apparatus for identifying crystal defects in emitter-base junctions of NPN bipolar transistors uses a test structure having an NP junction that can be inspected using passive voltage contrast. The test structure eliminates the collector of the transistor and simulates only the emitter and base. Eliminating the collector removes an NP junction between collector and substrate of a wafer allowing charge to flow from the substrate to emitter if the emitter-base junction is defective since only one NP junction exists in the test structure. In one embodiment, the test structures are located between dies on a wafer and may be formed in groups of several thousand.