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. 27, 2001
Filed:
Jul. 22, 1999
Vanguard International Semiconductor Corporation, Hsin-Chu, TW;
Abstract
A method of creating a DRAM capacitor structure, featuring a crown shaped storage node structure, has been developed. The crown shaped storage node structure, features the formation of an hemispherical grain, (HSG), silicon layer, only on a top portion of the structure, with the bottom portion of the crown shaped storage node structure, featuring non - HSG, or smooth surfaces. This configuration is achieved via creation of a capacitor opening, in a doped oxide - undoped oxide, composite insulator layer, used as the shape for subsequent formation of an amorphous silicon crown shaped structure. Selective removal of the overlying doped oxide layer, allows selective formation of an HSG silicon layer, only on the exposed top portion of the amorphous silicon crown shaped structure. Subsequent removal of the undoped oxide layer, exposes a bottom portion of the amorphous silicon crown shaped structure, featuring non - HSG silicon surfaces, allowing easier formation of a capacitor dielectric layer, specifically at the bottom corner of the crown shaped storage node structure.