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:
Dec. 10, 2002
Filed:
Jun. 22, 2001
David C. Ahlgren, Wappingers Falls, NY (US);
Gregory G. Freeman, Hopewell Junction, NY (US);
Feng-Yi Huang, Hacienda Heights, CA (US);
Adam D. Ticknor, Wappingers Falls, NY (US);
International Business Machines Corporation, Armonk, NY (US);
Abstract
A process for forming a bipolar transistor with a raised extrinsic base, an emitter, and a collector integrated with a CMOS circuit with a gate. An intermediate semiconductor structure is provided having CMOS and bipolar areas. An intrinsic base layer is provided in the bipolar area. A base oxide is formed across, and a sacrificial emitter stack silicon layer is deposited on, both the CMOS and bipolar areas. A photoresist is applied to protect the bipolar area and the structure is etched to remove the sacrificial layer from the CMOS area only such that the top surface of the sacrificial layer on the bipolar area is substantially flush with the top surface of the CMOS area. Finally, a polish stop layer is deposited having a substantially flat top surface across both the CMOS and bipolar areas suitable for subsequent chemical-mechanical polishing (CMP) to form the raised extrinsic base.