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:
Oct. 02, 2001
Filed:
Oct. 01, 1999
Jyh-Cheng You, I-Lan County, TW;
Lin-June Wu, Hsin-Chu, TW;
Taiwan Semiconductor Manufacturing Company, Hsin-chu, TW;
Abstract
The invention provides a method for forming a ROM cell surface implant region using a PLDD implant. A semiconductor structure is provided comprising a substrate having isolation structures thereon, which separate and electrically isolating a first area having a P-well formed in the substrate and a gate over the substrate, a second area having a N-well formed in the substrate and a gate over the substrate, and a third area having P-well and buried N+ regions formed in the substrate with second isolation structures overlying the buried N+ regions. A photoresist mask is formed exposing the first area, and impurity ions are implanted to form n-type lightly doped source and drain regions. The photoresist mask is removed and a new (PLDD/ROM) photoresist mask is formed exposing the second area and the third area. Impurity ions are implanted to simultaneously form p-type lightly doped source and drain regions and a ROM cell surface implant region region. The PLDD/ROM photoresist mask is then removed.