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. 22, 1988
Filed:
Mar. 30, 1987
Peter L Buchmann, Langnau a.Albis, CH;
Volker Graf, Wollerau, CH;
Peter D Hoh, Stormville, NY (US);
Theodor O Mohr, Wettswil, CH;
Peter Vettiger, Langnau a.Albis, CH;
International Business Machines Corporation, Armonk, NY (US);
Abstract
Process for producing temperature-stable undercut profiles for use in semiconductor fabrication. The process is based on the phenomenon of high etch-rate selectivity between RF- and LF- PECVD-grown silicon nitride films (12G and 13G, respectively) that are deposited on top of each other. By choosing proper film and process parameters, these PECVD nitride structures can be made stress-free: the tensile stress of the RF film (12G) compensates the compressive stress of the LF film (13G). Also disclosed is an application of a T-shaped structure (15), produced with the new process, in a method for fabricating fully self-aligned 'dummy' gate sub-micron MESFETs.