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:
Feb. 01, 1977
Filed:
Feb. 13, 1976
Joseph A Aboaf, Peekskill, NY (US);
Robert W Broadie, Hopewell Junction, NY (US);
Edward M Hull, La Grangeville, NY (US);
H Bernhard Pogge, Hopewell Junction, NY (US);
International Business Machines Corporation, Armonk, NY (US);
Abstract
A high power semiconductor device is formed by providing a semiconductor substrate of N.sup.- conductivity, rendering the backside of same porous as by subjecting same to anodic treatment carried out in a concentrated solution of hydrofluoric acid, converting the porous region to an N.sup.+ region, as by arsenic diffusion and forming an active device by conventional techniques in the top surface of the substrate. The method permits usage of high quality N.sup.- substrates and at the same time eliminates the requirement of growing thick epitaxial layers.