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:
Apr. 22, 2003
Filed:
Apr. 12, 2000
Other;
Abstract
A method for improving gate oxide thinning issue at trench corners is disclosed. The method comprises steps as follows. Firstly, a silicon substrate having a trench therein is provided. HDPCVD technology to form a first oxide layer on the sidewall and the bottom of the trench is carried out. After performing an etchback to leave the first oxide layer on the bottom of the trench, a second oxide layer is formed on the first oxide layer and on sidewalls of the trench by LPCVD technology. Thereafter, an isotropic etching is performed so as to remove a substantially portion of the second oxide layer and leave a remnant portion of second oxide layer on the trench corners. As a consequently, the trench corners are smooth. Finally, a thermal oxidation to form a third oxide layer on the sidewall of the trench is carried achieved to accomplish the gate oxide formation.