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:
Sep. 15, 1987
Filed:
Jun. 26, 1986
Howard K Leung, Austin, TX (US);
Bich-Yen Nguyen, Austin, TX (US);
John R Alvis, Austin, TX (US);
John Schmiesing, Round Rock, TX (US);
Motorola, Inc., Schaumburg, IL (US);
Abstract
A process is disclosed for fabricating a semiconductor device which includes a trench formed at the surface of the device substrate. The surface of the device substrate is oxidized and the oxide is patterned to form an opening which exposes a portion of the underlying surface. Ions are implanted through the opening and into the surface to form a damaged surface region which is coincident with the opening and extends under the edge of the oxide. A trench is etched by reactive ion etching using the opening in the oxide as an etch mask. The substrate, including the walls of the trench and the ion implant damaged surface portion under the edge of the oxide, is thermally oxidized. The oxidation rate is enhanced by the damage and causes a thicker oxide to grow in the damaged region which forms a collar around the intersection of the trench with the surface. Upon removing the oxide, the intersection of the trench with the surface is characterized by a rounded corner caused by the enhanced oxidation in that location during the oxidation.