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:
Jun. 04, 2013
Filed:
Sep. 12, 2011
Fabrication methods for t-gate and inverted l-gate structure for high frequency devices and circuits
Cindy X. Qiu, Brossard, CA;
Ishiang Shih, Brossard, CA;
Chunong Qiu, Brossard, CA;
Yi-chi Shih, Palos Verdes Estates, CA (US);
Julia Qiu, Brossard, CA;
Cindy X. Qiu, Brossard, CA;
Ishiang Shih, Brossard, CA;
Chunong Qiu, Brossard, CA;
Yi-Chi Shih, Palos Verdes Estates, CA (US);
Julia Qiu, Brossard, CA;
Other;
Abstract
In high frequency circuits, the switching speed of devices is often limited by the series resistance and capacitance across the input terminals. To reduce the resistance and capacitance, the cross-section of input electrodes is made into a T-shape or inverted L-shape through lithography. The prior art method for the formation of cavities for T-gate or inverted L-gate is achieved through several steps using multiple photomasks. Often, two or even three different photoresists with different sensitivity are required. In one embodiment of the present invention, an optical lithography method for the formation of T-gate or inverted L-gate structures using only one photomask is disclosed. In another embodiment, the structure for the T-gate or inverted L-gate is formed using the same type of photoresist material.