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. 01, 2005
Filed:
Mar. 19, 2002
Prashant Chavarkar, Goleta, CA (US);
Ioulia P. Smorchkova, Redondo Beach, CA (US);
Stacia Keller, Santa Barbara, CA (US);
Umesh Mishra, Santa Barbara, CA (US);
Wladyslaw Walukiewicz, Kensington, CA (US);
Yifeng Wu, Goleta, CA (US);
Prashant Chavarkar, Goleta, CA (US);
Ioulia P. Smorchkova, Redondo Beach, CA (US);
Stacia Keller, Santa Barbara, CA (US);
Umesh Mishra, Santa Barbara, CA (US);
Wladyslaw Walukiewicz, Kensington, CA (US);
Yifeng Wu, Goleta, CA (US);
Cree Inc., Goleta, CA (US);
Abstract
A Group III nitride based high electron mobility transistors (HEMT) is disclosed that provides improved high frequency performance. One embodiment of the HEMT comprises a GaN buffer layer, with an AlGaN (y=1 or y 1) layer on the GaN buffer layer. An AlGaN (0≦x≦0.5) barrier layer on to the AlGaN layer, opposite the GaN buffer layer, AlGaN layer having a higher Al concentration than that of the AlGaN barrier layer. A preferred AlGaN layer has y=1 or y1 and a preferred AlGaN barrier layer has 0≦x≦0.5. A 2DEG forms at the interface between the GaN buffer layer and the AlGaN layer. Respective source, drain and gate contacts are formed on the AlGaN barrier layer. The HEMT can also comprising a substrate adjacent to the buffer layer, opposite the AlGaN layer and a nucleation layer between the AlGaN buffer layer and the substrate.