Program efficiency relying on channel conditions at NOR-type flash memory device based on silicon-on-insulator (SOI)

Various types of flash memory devices are fabricated on silicon-on-insulator (SOI) substrate for efficient isolation and higher program efficiency nowadays. Since metal-oxide-semiconductor field effect transistors (MOSFETs) on SOI has a floating body and corresponding effects, it is quite difficult to predict the program efficiency of SOI-based NOR-type flash memory device making use of channel hot electron injection (CHEI) mechanism in program operation. The program efficiency is hard to control by back substrate bias unlike bulk silicon-based memory device, either. In this work, the dependence of program efficiency for SOI-based NOR-type flash memory device on channel conditions with regard to SOI thickness and channel doping concentration is thoroughly investigated by numerical simulation.