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:
Dec. 23, 2003
Filed:
Jun. 09, 2000
Chia-Ta Hsieh, Tainan, TW;
Yai-Fen Lin, Taichung, TW;
Hong-Cheng Sung, Hsin-chu, TW;
Di-Son Kuo, Hsinchu, TW;
Taiwan Semiconductor Manufacturing Company, Hsin-Chu, TW;
Abstract
A method is provided for forming a short and sharp gate bird's beak in order to increase the erase speed of a split-gate flash memory. This is accomplished in two embodiments where in the first, fluorine is implanted in the first polysilicon layer to form the floating gate. It is disclosed here that the implanting of fluorine increases the oxidation rate of the polysilicon and because of the faster oxidation, the polygate bird's beak that is formed attains a relatively short and sharp in comparison with conventional beaks. This has the attendant benefit of forming a relatively small memory cell, and the concomitant reduction in the erase speed of the cell. In the second embodiment, oxygen is used with the same favorable results. A third embodiment discloses the structure of a split-gate flash memory cell having a sharp bird's beak.