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. 11, 1986
Filed:
May. 31, 1985
Wolfgang M Feist, Burlington, MA (US);
Raytheon Company, Lexington, MA (US);
Abstract
A method for forming isolation regions in a semiconductor structure is provided. A mask comprising an upper and a lower layer of different materials is provided over the surface of the structure. A window is formed in the upper layer over the portions of the structure wherein the isolation regions are to be provided. Using the window in the upper layer as a mask, a larger window is formed in the lower layer by bringing a chemical etchant which etches only the lower layer into contact with the portions of the lower layer exposed by the window in the upper layer. The larger window formed in the lower layer is used as an etching mask to form an isolation groove, or depression, in the underlying semiconductor structure. The upper layer having the smaller window is used as an ion implantation mask for implanting particles into the bottom portion of the groove while masking the side portions of the grooves from the ions. With such method, lateral oxidation regions having self-registered anti-inversion regions which are located under the bottoms of the isolation regions and are spaced from the peripheries of the isolation regions by uniform, predetermined distances are obtained.