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:
Aug. 16, 2011
Filed:
Sep. 08, 2008
Su-tsai LU, Miaoli County, TW;
Wen-hwa Chen, Hsinchu, TW;
Hsien-chie Cheng, Hsinchu, TW;
Yun-chiao Chen, Taichung County, TW;
Su-Tsai Lu, Miaoli County, TW;
Wen-Hwa Chen, Hsinchu, TW;
Hsien-Chie Cheng, Hsinchu, TW;
Yun-Chiao Chen, Taichung County, TW;
Industrial Technology Research Institute, Hsinchu, TW;
Abstract
After a fabrication process intended to miniaturize semiconductor devices, a surface area of a stack capacitor in a random access memory (RAM) is significantly reduced and capacity thereof is thus decreased, which in turn causes the capacitor not able to function properly. The present invention provides a composite lower electrode structure consisting of an exterior annular pipe and a central pillar having concave-convex surfaces to increase a surface area of the capacitor within a limited memory cell so as to enhance the capacity. To reinforce intensity of a structure of the capacitor, the exterior annular pipe has an elliptic radial cross section and a thicker thickness along a short axis direction.