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:
Jul. 09, 2002
Filed:
Jun. 14, 2000
Applicant:
Inventors:
William F. Richardson, San Antonio, TX (US);
Yuji Sasaki, San Antonio, TX (US);
Assignee:
Other;
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
H01L 2/1331 ;
U.S. Cl.
CPC ...
H01L 2/1331 ;
Abstract
A low resistance bipolar transistor extrinsic base and method of manufacture. A layer of heavily doped polysilicon is deposited over an oxide layer on an npn silicon substrate and a window is formed through to an n doped region of the substrate. Epitaxial SiGe is grown on the polysilicon layer and within the window. Dopant from the polysilicon layer diffuses into the SiGe layer thereby lowering its resistance.