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:
Jan. 17, 2006
Filed:
Sep. 25, 2003
Shih-lung Chen, Taipei, TW;
Yueh-chuan Lee, Nantou, TW;
Shih-Lung Chen, Taipei, TW;
Yueh-Chuan Lee, Nantou, TW;
ProMOS Technologies Inc., Hsinchu, TW;
Abstract
A method for forming a volatile memory structure. A buried trench capacitor in each of a pair of neighboring trenches formed in a substrate. An asymmetric collar insulating layer is formed over an upper portion of the sidewall of each trench and has a high and a low level portions. A conductive layer is formed overlying the buried trench capacitor and below the surface of the substrate. The high level portion is adjacent to the substrate between the neighboring trenches and the low level portion is covered by the conductive layer. A dielectric layer is formed overlying the conductive layer. Two access transistors are formed on the substrate outside of the pair of the neighboring trenches, respectively, which have source/drain regions electrically connecting to the conductive layer. A volatile memory structure is also disclosed.