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. 27, 2004
Filed:
Feb. 01, 2002
Thomas J. Krutsick, Fleetwood, PA (US);
Agere Systems Inc., Allentown, PA (US);
Abstract
Complementary bipolar transistors are fabricated on a semiconductor wafer by forming, first and second electrodes corresponding to first and second complementary transistors, respectively. A first impurity is selectively introduced into the first and second electrodes. A third electrode corresponding to the first transistor is formed, the third electrode being self-aligned with and electrically isolated from the first electrode, and a fourth electrode is formed corresponding to the second transistor, the fourth electrode being self-aligned with and electrically isolated from the second electrode. A second impurity is selectively introduced into the third and fourth electrodes. First active regions of the first and second transistors are formed, whereby the first impurity diffuses into the first active regions. Likewise, second active regions of the first and second transistors are formed, whereby the second impurity diffuses into the second active regions. A reduction in the number of fabrication steps and/or masks is thereby achieved.