Dependence of Program Efficiency on Channel Conditions Regarding NOR-Type Flash Memory Devices Fabricated on a Silicon-on-Insulator (S01) Substrate

摘要

Flash memory devices are fabricated on a silicon-on-insulator (SOI) substrate to satisfy thedemand for higher program efficiency occasionally. However, since metal-oxide-semiconductorfield-effect transistors (MOSFETs) on SOI substrate have floating bodies and correspondingeffects, it is quite difficult to make a precise prediction of the program efficiency for SOI-basedNOR-type flash memory devices by making use of the channel hot electron injection (CHEI)mechanism in program operation. In this work, the dependence of the program efficiency forSOI-based NOR-type flash memory devices on the channel conditions with regard to the SOIthickness and the SOI doping concentration has been thoroughly investigated by using a numericaldevice simulation. The state of the silicon channel (fully/partially depleted channel) turns outto be strongly correlated with these process parameters that affect the hole accumulation, whichchanges the program efficiency.