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:
Dec. 06, 2005
Filed:
Nov. 19, 2003
Patrick Poveda, Villedomer, FR;
Patrick Poveda, Villedomer, FR;
STMicroelectronics S.A., , FR;
Abstract
A method for forming narrow trenches in a silicon substrate, comprising the steps of: etching the substrate to form first trenches separated by first silicon ribs; performing a thermal oxidation of the substrate to form a silicon oxide layer around the substrate, to obtain second trenches and second silicon ribs; filling the second trenches with fingers of an etchable material; etching the oxide down to the upper surface of the second ribs while keeping oxide portions between said material fingers and the second ribs; etching away the second silicon ribs and said material fingers; etching the oxide to expose the substrate at the bottom of the oxide portions, while keeping oxide fingers; and etching the substrate between the oxide fingers to form narrow trenches in the substrate.