Comparison of TID response in core, input/output and high voltage transistors for flash memory

Total ionizing dose (TID) response in core, input/output (I/O) and high voltage (HV) transistors for 180 nm flash memory technology is comprehensively investigated. Great influence by irradiation is observed for all these transistors, including threshold voltage shift, appearance of subthreshold hump effect and increase of off-state leakage current. Also, we found that the higher the drain voltage, the larger increase of the off-state leakage, which is well known as radiation enhanced drain induced barrier lowering (DIBL) effect. Radiation enhanced DIBL effect leads to worse characteristic degradation of transistor. The HV transistor is the most sensitive parts in flash memory control circuitry.