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:
Jun. 06, 2000
Filed:
Jun. 01, 1999
Applicant:
Inventors:
Assignee:
Mosel Vitelic, Inc., Hsinchu, TW;
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
H01L / ;
U.S. Cl.
CPC ...
438424 ; 438425 ; 438702 ;
Abstract
A method to prevent the formation of a thinner portion of insulating layer, especially a gate oxide layer, at the junction between the side walls and the bottom insulator is disclosed. First, a pad oxide layer is formed on the side walls and the bottom of the trench. Next, a bottom oxide is formed on the lower portion of the trench. Then, the upper portion of the bottom oxide and the exposed pad oxide layer are removed by wet etching to leave a bottom oxide having a concave surface. Next, the conformal gate oxide layer is grown on the exposed side walls of the trench.