The effects of gamma irradiation on threshold voltage and channel mobility models of PMOS

This paper presents the effects of gamma irradiation on threshold voltage and mobility models of PMOS. The devices with a gate oxide thickness of 15 nm fabricated in an 0.8-micron CMOS technology were measured and tested. The electrical properties were collected pre-irradiation and after the exposure by a⁶⁰Co gamma-ray source in the dose range of 1 to 10 kGy, transient dose = 290.68 Gy/hr. The results show that the threshold voltage of big MOS at zero substrate bias (VT0) increased approximately 28%, but the low field surface mobility (UO) and the maximum transconductance parameter (K0) decreased in the same value by 7.5% and the THETA (? ) parameter decreased by 28%. All parameters caused the saturation drain current of big MOS to decrease 16%. For short channel effects, the saturation drain current decreased more. Finally, the short channel model parameter should be investigated and discussed in future.