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:
Oct. 22, 1991
Filed:
Mar. 15, 1991
Christoph S Harder, Zurich, CH;
Wilhelm Heuberger, Richterswil, CH;
Peter D Hoh, Hopewell Junction, NY (US);
David J Webb, Ruschlikon, CH;
International Business Machines Corporation, Armonk, NY (US);
Abstract
A process for forming the ridge structure of a self-aligned InP-system, double heterostructure (DH) laser, particularly useful for long wavelength devices as required for signal transmission systems includes a thin Si.sub.3 N.sub.4 layer (41) inserted between a photoresist mask (42) that defines the ridge structure, and a contact layer (35). Using a Si.sub.3 N.sub.4 layer (4) deposited at a high plasma excitation frequency (RF) for adhesion promotion, and a low frequency deposited (LF) Si.sub.3 N.sub.4 layer (43) for device embedding, provides for the etch selectively required in the process step that is used to expose the contact layer to ohmic contact metallization deposition.