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:
Jul. 24, 2001
Filed:
Nov. 01, 1999
Jui-Tsen Huang, Taipei, TW;
Chien-Hua Tsai, Tai-Chung, TW;
United Microelectronics Corp., Hsin-Chu, TW;
Abstract
A semiconductor wafer comprises a silicon substrate, and a dielectric layer. A gate is formed on the dielectric layer. A first silicon oxide layer is uniformly formed on the semiconductor wafer. A first ion implantation process is performed to form two doped areas on the silicon substrate that are used as two lightly doped drains of a MOS transistor. A second silicon oxide layer is formed on the semiconductor wafer. A sacrificial layer is formed on the second silicon oxide layer. A first etching process is performed to remove the sacrificial layer on top of the gate, causing the gate to protrude from the remaining sacrificial layer for a predetermined height. A second etching process is performed to remove the first and second silicon oxide layers on the protruding portion of the gate. After removing the sacrificial layer completely, a silicon nitride layer is uniformly formed on the semiconductor wafer. A third etching process is performed to vertically remove the silicon nitride layer on top of the gate, thereby forming a spacer. Finally, a second ion implantation process is performed to form two doped areas on the silicon substrate, which are used as source and drain of the MOS transistor.