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:
May. 17, 2011
Filed:
Mar. 27, 2008
Dong Xu, Nashua, NH (US);
Gabriel Cueva, Bedford, NH (US);
Pane-chane Chao, Nashua, NH (US);
Wendell Kong, Hollis, NH (US);
Dong Xu, Nashua, NH (US);
Gabriel Cueva, Bedford, NH (US);
Pane-chane Chao, Nashua, NH (US);
Wendell Kong, Hollis, NH (US);
BAE Systems Information and Electronic Systems Integration Inc., Nashua, NH (US);
Abstract
A method for fabricating ultra-short T-gates on heterojunction field effect transistors (HFETs) comprising the steps of (a) providing a coating of three layers of resists, with polymethylmethacrylate (PMMA) with high molecular weight on the bottom, polydimethylglutarimide (PMGI) in the middle, and PMMA with low molecular weight on the top; (b) in a first exposure, exposing and developing the layers with a dose of a developer that is high enough to allow the developer to break the top PMMA but low to avoid contributing significantly to the overall dose received in the bottom PMMA layer; and (c) in a second exposure, using an exposure and developing process to define 0.03-0.05 um openings in the bottom PMMA layer.