Program/erase speed, endurance, retention, and disturbance characteristics of single-poly embedded flash cells

Abstract

N-channel and P-channel single-poly embedded flash (eflash) memory cells were implemented in a standard CMOS logic process. Among the different configurations based on standard I/O devices, the N-channel cell with a PMOS-PMOS-NMOS combo and the P-channel cell with an NMOS-NMOS-PMOS combo were found to be most attractive in terms of program/erase performance, while the cell with a coupling device having P+ poly showed longer retention characteristic than the cells with a coupling device having N+ poly. Negligible program disturbance and floating gate coupling were observed in all cell types.