Process for forming the ridge structure of a self-aligned semiconductor laser
CA 2039875 C · Owner: Harder, Christoph S. · Inventors: Hoh, Peter D.; Webb, David John; Heuberger, Wilhelm
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
A process for forming the ridge structure of a self-aligned semiconductor laser, particularly useful for long wavelength devices as required for signal transmission systems. Described is the process as applied to an InP-system double heterostructure, (DH) laser. A thin Si3N4 layer (41) is inserted between the photoresist mask (42) that defines the ridge structure, and the contact layer (35). This results in improved adhesion and reduced etch undercutting whereby the ohmic contact area is increased, heat development decreased and device properties improved. Using a Si3N4 layer (41) deposited at a high plasma excitation frequency (RF) for adhesion promotion, and a low frequency deposited (LF) …
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Listed from its CIPO record in Patent Yard's archive of Canadian patents past their term. Its claims, description and drawings are in the CIPO record and on Google Patents, and the Claude kit works from them.
Why it's free to use
- Filed April 5, 1991 and granted May 3, 1994. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended April 5, 2011.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by April 5, 2013.
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Everything on this page comes from the CIPO record linked above. Contains information licensed under the Open Government Licence – Canada.