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:
Jan. 20, 2004
Filed:
Feb. 02, 2001
Augusto L. Gutierrez-Aitken, Redondo Beach, CA (US);
Aaron K. Oki, Torrance, CA (US);
Eric N. Kaneshiro, Torrance, CA (US);
Dwight C. Streit, Seal Beach, CA (US);
Northrop Grumman Corporation, Los Angeles, CA (US);
Abstract
Reduction in the base to collector capacitance of a heterojunction bipolar transistor, and, improved high frequency performance is achieved using existing materials and processes by undercutting the collector ( ) under the base ( ) along two parallel sides of the base mesa ( —FIG. ), and providing a sloped collector edge ( —FIG. ) along the remaining two parallel sides of the base. The foregoing is accomplished by selective etching and with the four sides of the mesa regions oriented as a non-rectangular parallelogram ( —FIG. ) in which one pair of sides is in parallel with one of the said [ ] and [ {overscore (1)}] planes of the crystalline structure and the other pair of sides in parallel with one of the [ ] and [ {overscore (1)} {overscore (1)}] planes of the crystalline structure.