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:
Feb. 04, 2003
Filed:
Apr. 05, 2002
Nien-Yu Tsai, Hsinchu, TW;
Yung-Ching Wang, Hsinchu, TW;
ProMOS Technologies Inc., Hsinchu, TW;
Abstract
A method of forming a shallow trench in a specific region located between two adjacent deep trench capacitor constructions on a semiconductor substrate, each the deep trench capacitor construction having a collar construction and a conductor construction is provided. The method of forming a shallow trench includes steps of (a) defining a mask by forming a mask layer on the semiconductor substrate which has the deep trench capacitor constructions, (b) performing a first etching process with respect to the regions, which is not covered by the mask, so as to form a first depth trench, in which the first etching process has a relatively high selectivity ratio of the conductor construction relative to the mask, and (c) performing a second etching process with respect to the first depth trench so as to form a second depth trench, in which the second etching process has a selectivity ratio of the conductor construction relative to the collar construction substantially close to 1.