Si-like low-frequency noise characteristics of 4H-SiC MOSFETs
The 1/f noise in 4H-SiC MOSFETs with epitaxial channel has been investigated systematically for the first time. It was shown that in the samples with NO post-oxidation annealing and epitaxial channel, the dependence of noise on gate voltage has a 'classical' Si-like form. Such a kind of dependence manifests that the density of negative oxide traps responsible for 1/f noise, Ntv, does not depend on Ec–EF (Ec is a position of the bottom of conductivity band; EF is a position of the Fermi level). The Ntv was found to be ~ 2 × 1019 cm−3 eV−1. Interface trap density and its dependence on energy position, Dit(Ec–EF), were extracted from temperature dependences of the threshold voltage Vt and from transfer current–voltage characteristics in the subthreshold regime.