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. 08, 2005
Filed:
Jun. 09, 2003
Miroslav Micovic, Newbury Park, CA (US);
Tahir Hussain, Calabasas, CA (US);
Paul Hashimoto, Los Angeles, CA (US);
Janna Ruth Duvall, Lawndale, CA (US);
Miroslav Micovic, Newbury Park, CA (US);
Tahir Hussain, Calabasas, CA (US);
Paul Hashimoto, Los Angeles, CA (US);
Janna Ruth Duvall, Lawndale, CA (US);
HRL Laboratories, LLC, Malibu, CA (US);
Abstract
A process and related product in which ohmic contacts are formed in High Electron Mobility Transistors (HEMTs) employing compound substrates such as gallium nitride. An improved device and an improvement to a process for fabrication of ohmic contacts to GaN/AlGaN HEMTs using a novel two step resist process to fabricate the ohmic contacts are described. This novel two-step process consists of depositing a plurality of layers having compounds of Group III V elements on a substrate; patterning and depositing a first photoresist on one of the layers; etching recessed areas into this layer; depositing ohmic metals on the recessed areas; removing the first photoresist; patterning and depositing a second photoresist, smaller in profile than the first photoresist, on the layer; depositing more ohmic metal on the layer allowing for complete coverage of the recessed areas; removing the second photoresist, and annealing the semiconductor structure.