INVESTIGATION OF INTERFACIAL STATES IN MIS STRUCTURES BY A SINGLE-FREQUENCY ADMITTANCE METHOD

Two models of tunneling charge exchange on interfacial stales buried i n the insulator are examined. In one model the spatial distribution of these states is assumed to be uniform and in the other model the volu me density of traps decreases exponentially with increasing depth. Ana lytical expressions are obtained for the width and position of the pea k in the normalized-conductance curves in both models, and the accurac y and limitations of these expressions are indicated. A new procedure for investigating interfacial states by the admittance method is propo sed, based on the use of G-V characteristics of metal-insulator-semico nductor (MIS) structures measured at a fixed frequency. (C) 1997 Ameri can Institute of Physics.