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. 13, 2001
Filed:
Aug. 06, 1999
Tse-Liang Ying, Hsin-Chu, TW;
Wen-Chuan Chiang, Hsin-Chu, TW;
Cheng-Ming Wu, Kao-Hsiung, TW;
Yu-Hua Lee, Hsinchu, TW;
Taiwan Semiconductor Manufacturing Company, Hsin-Chu, TW;
Abstract
A new method is provided to create a gradated dopant concentration in the contact plug of DRAM devices whereby a high dopant concentration is present at the bottom of the plug and a low dopant concentration is present at the top of the plug. Two layers of dielectric are deposited; the upper layer serves as a layer to adjust the dopant concentration in the lower layer. This adjustment is done by Rapid Thermal anneal of both layers of dielectric. After the dopant concentration has been adjusted, the upper layer of dielectric is removed and the upper section of the contact node is formed using lightly doped poly. The high dopant concentration at the bottom of the contact plug results in low contact resistance between the plug and the underlying silicon substrate. A low dopant concentration at the top surface of the contact plug results in low oxidation of the surface of the plug.