A single-poly EEPROM cell structure compatible to standard CMOS process

A novel cell structure is proposed for low cost, low capacity EEPROMs. The cell is composed of an NMOSFET and a MOS capacitor with a shared poly-silicon layer that functions as the floating gate of the cell. This nonvolatile cell can be fabricated by a standard CMOS process technology without any extra steps. Detailed analyses are carried out for the dependence of the performance on the capacitance ratios C-C/C-D between the NMOSFET C-D and the MOS capacitor C-C. The efficiencies of program/erase operations, the ability of data retention and the cyclic endurance are also discussed. (c) 2007 Elsevier Ltd. All rights reserved.