Experimental evaluation of coulomb-scattering-limited inversion-layer mobility of n-type metal-oxide-semiconductor field-effect transistors on Si(100), (110), and (111)-surfaces: Impact of correlation between conductivity mass and normal mass

The inversion-layer electron mobility limited by Coulomb scattering due to interface states (μ_it) and substrate impurities (μ_sub) are experimentally evaluated on Si n-type metal-oxide-semiconductor field-effect transistors (MOSFETs) at the surfaces of Si(100), (110), and (111). The inversionlayer mobility is measured by the split C-V method and μ_it and μ_sub are extracted using Matthiessen's rule. μ_it exhibits almost the same behavior irrespective of the different surface orientations, while μ_sub has the surface orientation dependence. The very weak surface orientation dependence of μ_it are due to the correlation between the inversion layer thickness (Z_ave) determined by the normal mass (m_z) and the weighed average value of conductivity mass (m_c-ave) under multi valley occupation. The surface orientation dependence of μ_sub is basically explained by the mc ave difference.