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:
Dec. 11, 2001
Filed:
Jan. 28, 2000
Chuan-Fu Wang, Taipei Hsien, TW;
Hsi-Mao Hsiao, Hsin-Chu, TW;
United Microelectronics Corp., Hsin-Chu, TW;
Abstract
A method is disclosed for forming the lower storage node and contact for capacitors on a semiconductor wafer. The method includes an etch back process to remove a portion of the silicon oxide layer around the mouth of the contact hole to produce a rounded shoulder where the walls of the contact hole meet the face of the silicon oxide layer. When a contact plug is formed during a subsequent deposition process, the rounded shoulder results in local enlargement of the contact plug as well as filleting of reentrant corners. The contact plug therefore sustains substantially reduced mechanical stress during subsequent wafer cleaning processes. This stress reduction results in a reduced rate of lower node collapse and increased production yield of finished product.