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:
Mar. 14, 2000
Filed:
Mar. 17, 1998
Meng-Jin Tsai, Hsinchu Hsien, TW;
Cheng-Han Huang, Hsinchu, TW;
United Microelectronics Corp., Hsin-Chu, TW;
Abstract
A method for manufacturing mixed-mode devices that can eliminate watermarks resulting from the formation of residues at the dead corner space of an inverted trapezium-shaped structure at the upper end of a shallow trench during dual gate-oxide processing operation. This method uses the same chemical processing conditions for etching the oxide layer and the removal of photoresist layer, so that no watermarks remain after the etching and cleaning processes. MOS transistors are formed over the thin gate oxide layer region and the thick gate oxide region are of, two types, each having a different gate oxide layer thickness so that each has a different operating voltage.