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:
Sep. 16, 2003
Filed:
Dec. 04, 2001
Taiwan Semiconductor Manufacturing Company, Hsin-Chu, TW;
Abstract
A semiconductor EEPROM device and a method for making it are achieved. The EEPROM device is a novel twin-bit cell structure with adjacent floating gates having a common control gate and common bit-line contact in each cell area. In each cell area a first and second floating gate is formed. Source areas are formed in the substrate adjacent to the outer edges of the floating gates and a drain area is formed between and adjacent to the floating gates. A gate oxide is formed over the floating gates. A control gate is formed over the drain area and patterned to also partially extend over the floating gates. The control gate is also patterned to provide a recess for a bit-line contact to the drain area. The recess results in reduced cell area and the non-critical overlay of the control gate over the floating gates results in relaxed overlay alignment.