On the energy spectrum of the state on the gallium arsenide-silicon nitride interface

Abstract

1. The surface states densities on the interface GaAs-Si3N4 [Nss ≈ (1–3)·1012 cm−12] are determined from investigations of the C-V characteristic. An essential increase in their concentration at the bottom of the conduction band is shown. 2. The conductivity in the space charge domain of n-type gallium arsenide is investigated as a function of the field electrode potential, and the mobility of the field effect is calculated for different values of Vc. A section with a drop in conduction is detected in the enrichment domain. The high mobilities of the field effect for negative Vc permit the proposal of a n-GaAs-Si3N4-M structure (with silicon nitride obtained from hydrazine and silicon tetrachloride) to produce a field transistor operating in the depletion mode. 3. The essential influence of the disordered domain of gallium arsenide near the surface on the electronic processes in the space charge domain is detected. The nature of the growth in surface states densities in the (Ec; Ec−0.5 eV) energy domain agrees with the disordering model; the presence of 1.0–1.4 eV light absorption bands in the photo-capacitance spectra, which we associate with electron transitions from the valence band into the fluctuation states of the disordered domain of gallium arsenide near the boundary, is also a confirmation.