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. 10, 1992
Filed:
Jun. 14, 1990
John M Pierce, Palo Alto, CA (US);
Sung T Ahn, Nara, JP;
National Semiconductor Corp., Santa Clara, CA (US);
Abstract
An integrated circuit device is fabricated upon a semiconductor wafer by first forming a stop layer upon the surface of the wafer. Holes are formed through the stop layer and wells are formed in the semiconductor material of the semiconductor wafer below the openings. A dielectric layer is formed over the the surface of the device substantially filling the wells and covering the stop layer. The dielectric layer is then planarized to substantially the level of the stop layer. A PAD oxide layer is provided between the stop layer and the surface of the semiconductor device. Conventional thin film oxidation of the wells and implants into the side walls of the wells are performed. An abrasive mechanical polisher is used to perform the planarization wherein the mechanical polisher is provided with the self-stopping feature when it encounters the stop layer.