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. 01, 1986
Filed:
Feb. 29, 1984
Lawrence A Goodman, Plainsboro, NJ (US);
Alvin M Goodman, Princeton Township, Mercer County, NJ (US);
Herman F Gossenberger, North Brunswick, NJ (US);
RCA Corporation, Princeton, NJ (US);
Abstract
A method for revealing the presence of heavy metal impurities that may have been introduced during the formation of a layer, such as the deposition of an epitaxial layer on a semiconductor substrate, uses the constant-magnitude steady-state surface photovoltage (SPV) method for determining the minority-carrier diffusion length by essentially two determination steps. A large ratio of the respective diffusion lengths determined before (actually measured or based on a priori knowledge of similar material) and after the epitaxial deposition step is indicative of the presence of a heavy metal impurity in the epitaxial layer. The method is based on the fact that the contaminating metal distributes itself substantially uniformly not only through the epitaxial layer but also throughout the substrate.