Influence of ΦMS(T) in the determination of the Si-SiO2surface states

The determination of fast surface states at the Si-Si02system by the Gray-Brown low-temperature technique is carefully analyzed. Included in this analysis is the variation of the semiconductor work function with the temperature and the doping impurity partial ionization at low temperature. It is shown that particularly the influence of the semiconductor work function is very significant. For instance, we obtained for an Si-SiO2system a number of surface states, with energy levels between 0.32 and 0.53 eV,N_{fs} simeq 8.5 times 10^{9}cm^-2orN_{fs} simeq 1.0 times 10^{11}cm^-2, the difference due to the influence of the semiconductor work function only.