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. 15, 1994
Filed:
Feb. 03, 1993
Hsiang-Ming J Chou, Hsinchu, TW;
Industrial Technology Research Institute, Hsinchu, TW;
Abstract
A method for the fabrication of high density dynamic random access memory (DRAM) devices with particular emphasis on the capacitor formation. The capacitor is formed using layers of doped and undoped polysilicon. The layers are patterned anisotropically so as to have their remaining portions over the planned capacitor areas, wherein a portion of the layers remains over both the gate structure and the field oxide areas. Then selective etching of the portion of doped polysilicon layer is accomplished using phosphoric acid at a temperature of more than abut 140.degree. C. to create an undercut of the undoped polysilicon layer. The capacitor is completed using a dielectric layer and a top electrode layer.