Different temperature dependence of mobility in n- and p-channel 4H-SiC MOSFETs

Abstract

Abstract The impact of interface state density (D it) near the conduction band edge (E C) and the VB edge (E V) on the field-effect mobility (μ FE) of NO- and N2-annealed n- and p-channel MOSFETs was investigated. With lowering the temperature, μ FE of n-channel MOSFETs decreased whereas μ FE increased in p-channel devices. Despite the comparable D it values near E C and E V, p-channel MOSFETs have less trapped carriers due to a deeper surface Fermi level caused by the larger effective masses of holes, resulting in smaller Coulomb scattering, and this may cause the different temperature dependence of μ FE in n- and p-channel MOSFETs.