Gamma Irradiation Effects on 4H-SiC MOS Capacitors and MOSFETs
The effects of gamma radiation on field effect mobility and threshold voltage have been studied for lateral n-channel 4H-SiC MOSFETs passivated with nitric oxide. MOS capacitors (n and p) and n-channel lateral MOSFETs were irradiated unbiased (floating contacts) for a total gamma dose of 6.8Mrad (Si). The MOS capacitors were used to study the radiation-induced interface traps and fixed oxide charge that affect the performance of the MOSFETs. Radiationinduced interface traps were observed near the SiC valence band edge and just above mid-gap, and field effect channel mobility was reduced by 18-20% following irradiation. Even so, 4HMOSFETs appear to be more radiation tolerant than Si devices.
Robert P. Devaty, David J. Larkin and Stephen E. Saddow
A. C. Ahyi et al., "Gamma Irradiation Effects on 4H-SiC MOS Capacitors and MOSFETs", Materials Science Forum, Vols. 527-529, pp. 1063-1066, 2006