We find that atomic-scale mechanisms for bias-temperature instabilities (BTIs) in SiC/SiO2 structures can differ significantly from those in Si/SiO2 structures. The measured effective-activation energies for BTI in 4H-SiC metal-oxide-semiconductor capacitors, 0.23±0.02 eV for p-type and 0.12±0.02 eV for n-type, are essentially identical to the respective dopant ionization energies, which are much larger than in Si. This suggests a key role for carrier release from deep dopants for BTI in SiC. In addition, asymmetric degradation is observed under switched-bias stress in p-type and n-type SiC, as a result of the reconfiguration of O vacancies in SiO2 layer after hole capture.
AlGaN/GaN high electron mobility transistors (HEMTs) irradiated with 1.8-MeV protons show more relative degradation in RF power/current gain, cutoff frequency , and maximum oscillation frequency than DC transconductance. These result from radiation-induced increases in fast bulk and surface trap densities, as well as increasing impedance mismatch at high frequencies with increasing proton fluence.-rich MBE devices show less degradation in DC transconductance, but more degradation in RF gain than Ga-rich devices.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.