Hole mobility in p-type silicon accumulation layers

The hole mobility in the accumulated p-type silicon surface has been determined by combined drain conductance and capacitance versus voltage measurements on metal-oxide-silicon field-effect transistors over a wide range of temperatures (78≤T≤425 K), substrate doping concentrations (1016≤NA ≤1.2×1018 cm−3), and surface electric fields (2×105≤FS ≤2×106 V/cm). The surface charge density of holes induced in the accumulation layer has been determined by comparing experimental and theoretical capacitance-voltage characteristics that have been calculated allowing for complete degeneracy of the hole gas and incomplete ionization of acceptors (boron). As a secondary result, the ionization energy of boron in silicon and the hole mobility in the bulk of the semiconductor have been determined as a function of temperature and boron concentration.