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:
Nov. 01, 2011
Filed:
Oct. 05, 2009
Applicant:
Detlef Wilhelm, Regensburg, DE;
Inventor:
Detlef Wilhelm, Regensburg, DE;
Assignee:
Infineon Technologies AG, Neubiberg, DE;
Attorneys:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
H01L 21/8249 (2006.01);
U.S. Cl.
CPC ...
Abstract
One or more embodiments of the invention relate to a method of making a heterojunction bipolar transistor, including: forming a collector layer; forming a stack of at least a second dielectric layer overlying a first dielectric layer, the stack formed over the collector layer; removing a portion of each of the dielectric layers to form an opening through the stack; and forming a base layer within the opening.