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. 19, 2002
Filed:
Mar. 19, 2001
Taiwan Semiconductor Manufacturing Company, Hsin-chu, TW;
Abstract
A process for forming self-aligned, twin well regions for a CMOS device, without the use of an oxidation retarding silicon nitride layer, has been developed. A first ion implantation procedure is used to place N type ions in a first portion of a semiconductor substrate, followed by a wet thermal oxidation procedure resulting in the growth of a thick silicon dioxide layer on the N type ions, in the first portion of the semiconductor substrate, while growing a thin silicon dioxide layer on a second portion of the lightly doped, P type semiconductor substrate. A second ion implantation procedure places P type ions through the thin silicon dioxide layer, into the second portion of the semiconductor substrate, while the thick silicon dioxide layer prevents the P type ions from reaching the first portion of the semiconductor substrate. A subsequent anneal procedure results in the formation of a N well region, in the first portion of the semiconductor substrate, self-aligned to the formed P well region, located in the second portion of the semiconductor substrate.