Performance of gamma irradiated p-channel 6H-SiC MOSFETs: high total dose

We present the first observation of total dose effects of gamma-ray irradiation on enhancement mode 6H-SiC p-channel MOSFETs. The electrical characterization of these transistors was performed before and after irradiation up to a total dose of 10/sup 8/ rad (SiO/sub 2/) by measuring the drain-source current (I/sub ds/) as a function of gate voltage (V/sub g/) and drain-source voltage (V/sub ds/). These transistors were compared to 6H-SiC n-channel MOSFETs. The p-channel devices remain fully functional up to 10/sup 6/ rad (SiO/sub 2/), while the n-channel devices are fully functional through 10/sup 8/ rad (SiO/sub 2/). We found that the generation of radiation-induced interface states in the n-channel transistors is substantially lower than that of the p-channel devices.