INVESTIGATIONS OF GOLD SURFACE-STATE ENERGY-LEVELS IN GOLD-DOPED MOS-TRANSISTORS

Measurements of threshold voltage for conduction of both p- and n-channel gold-doped and non-gold-doped MOS (111) transistors with variation in temperature from 300 K to 80 K reveal two blocks of gold acceptor surface states. One is at 0. 12 eV from the conduction band edge and the other at 0. 1 eV from the valence band edge, and a further rise in surface state charge close to the valence band edge suggests another gold energy level near the band edge. Hall-effect measurements also confirm these gold energy levels near the band edge.