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. 16, 1999
Filed:
Dec. 24, 1997
Yau-Kae Sheu, Hsinchu, TW;
United Semiconductor Corp., Hsin-Chu, TW;
Abstract
A split-gate flash memory cell structure comprising a semiconductor substrate having a gate oxide layer already formed thereon. A first gate is then formed over the gate oxide layer, and a cross-section of the first gate contains two corners, one of which is a sharp corner. An insulating dielectric layer is then formed over the first gate. The insulating dielectric has a lens-shaped cross-section located above the sharp corner. Next, a second gate is formed over the insulating dielectric layer, and surrounded the first gate. A first doped region is formed in the substrate below the sharp corner. Then, a second doped region is formed in the substrate located on the other side of the first gate just opposite the first doped region, furthermore, the second doped region is separated from the first gate by a distance. There is a channel region between the first doped region and the second doped region, and the sharp corner of this invention is located above the semiconductor substrate outside the channel region.