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. 27, 2001
Filed:
Mar. 06, 1998
Kuo-Tung Sung, Hsinchu, TW;
Huoy-Jong Wu, Taichung, TW;
Other;
Abstract
Methods to improve cell performance in ROM semiconductor integrated circuit devices, in particular split gate cell flash EEPROM devices, without the need for increasing cell size or for decreasing tunnel oxide thickness. The threshold voltage under a first gate electrode (,) is adjusted using a first impurity introducing step, such as an ion implant, and the threshold voltage under a split gate electrode (,) is also adjusted using a second impurity introducing step, such as an ion implant. Depending on the type of cell used, the first gate electrode or the split gate electrode may be used as a floating gate electrode and the threshold voltage under the floating gate electrode may be adjusted separately from the other gate electrode to provide improved cell erase performance, with or without increasing the cell size or decreasing the tunnel oxide thickness.