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:
Feb. 28, 1989
Filed:
May. 05, 1988
Kabushiki Kaisha Toshiba, Kawasaki, JP;
Abstract
An SiO.sub.2 insulating layer is formed on an Si substrate, and an Si.sub.3 N.sub.4 insulating layer is formed on the SiO.sub.2 layer. A notch is formed in the Si.sub.3 N.sub.4 layer using a resist film as a mask. The SiO.sub.2 layer is etched using the Si.sub.3 N.sub.4 layer as a mask, thereby forming an opening larger than the notch cut in the SiO.sub.2 layer. As a result, the Si.sub.3 N.sub.4 layer extends over the opening in an overhanging manner. When As.sup.+ ions are implanted in the periphery of the notch of the Si.sub.3 N.sub.4 layer, the ion-implanted portion of the Si.sub.3 N.sub.4 layer is arcuated toward the base region. When a metal such as Ti is deposited on the arcuated portion, the metal is also deposited on the arcuated portion and the portion of the emitter region matching with the notch, thereby forming an emitter electrode portion.