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:
May. 11, 2001
Li-Wu Tsao, Keelung, TW;
Nanya Technology Corporation, Taoyuan, TW;
Abstract
A method of forming a uniform collar oxide layer over an upper portion of a sidewall of a trench extending into a semiconductor substrate is disclosed. A silicon oxide layer and a mask layer are conformally formed on a single-crystal silicon substrate having a trench. A photoresist layer is formed on the mask layer, a part of the photoresist layer is then removed to make the top surface of the photoresist layer lower than the top surface of the single-crystal silicon substrate with a distance. After the mask layer and the silicon oxide layer, which are not covered by the remaining photoresist layer, are removed, the remaining photoresist layer is removed. Then, an ion implantation process is proceeded to make the oxidation rates in the ( ) and ( ) orientations existing in the sidewall of the trench equal to each other. After the sidewall of the trench is treated, a local oxidation is executed to form a uniform collar oxide layer.