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:
Sep. 18, 1984
Filed:
Dec. 07, 1983
Eliezer Kinsbron, Highland Park, NJ (US);
AT&T Bell Laboratories, Murray Hill, NJ (US);
Abstract
A method for forming a shallow and highly concentrated arsenic doped surface layer in a silicon bulk region includes the steps of forming an arsenic doped polysilicon layer in contact with a preselected area of a bulk region surface in which the surface layer is to be formed and completely oxidizing the polysilicon layer at a rate exceeding the rate at which arsenic diffuses in the bulk region. Since arsenic has a relatively high silicon/silicon dioxide segregation coefficient and the oxidation rate exceeds the arsenic diffusion rate, arsenic accumulates at the silicon dioxide/silicon interface during oxidation, and nearly all of the arsenic in the region of the polysilicon layer above the preselected area is driven into the bulk region surface by the oxidation to form an impurity layer having a very high surface concentration of arsenic.