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:
Mar. 16, 1982
Filed:
Mar. 24, 1980
Chakrapani G Jambotkar, Hopewell Junction, NY (US);
International Business Machines Corporation, Armonk, NY (US);
Abstract
Bipolar transistor devices are formed by employing polysilicon base contacts self-aligned with respect to a diffusion or ion implantation window used to form emitter, intrinsic base and raised subcollector regions. The polysilicon acts as a self-aligned impurity source to form the extrinsic base region therebelow and, after being coated with silicon dioxide on its surface and along the sidewalls of the diffusion or ion implantation window, as a mask. Directional reactive ion etching is used to form a window in the silicon dioxide while retaining it along the sidewalls. Ion implantation, for example, may be used to form, through the window, an emitter, intrinsic base and raised subcollector region. The silicon dioxide is used as an insulator to separate the emitter contact from polysilicon.