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:
Aug. 31, 1999
Filed:
Dec. 22, 1998
Chih-Yuan Hsiao, Feng-Shan, TW;
United Microelectronics Corp., Hsinchu, TW;
Abstract
A method for forming a protection circuit that starts with forming a first-type well and a second-type well on a first-type substrate. By forming isolations, a first active region is defined within the second-type well, and a second active region, a third active region and a fourth active region are defined within the first-type well. A first polysilicon layer is formed on the substrate and patterned to expose the third and the fourth active regions. A second polysilicon layer is formed on the substrate and patterned into a first gate that connects the first and the third active regions, and a second gate that connects the second and the fourth active regions. Then, by performing a first-type implantation process, the first gate is turned into a first-type gate. First-type source/drain regions are formed in the first active region, and first-type contacts are formed in the third active region as well. Similarly, the second gate is turned into a second-type gate, second-type source/drain regions are formed in the second active region, and second-type contacts are formed in the fourth active region by performing a second-type implantation process.