(Invited) GaAs MIS Structures–Hopeless or Promising?

Abstract

High density of interface states introduces uncertainties in the study of GaAs MIS structures; the complex chemical nature of the Ga–As-oxide system has posed an additional problem. The interface states were found to have discrete energy positions about 0.7 and 0.9 eV below the conduction band minimum (rather than a continuous spectrum of energies) which are also characteristic of GaAs “real” surfaces and independent of the insulator. On the basis of the energy position and dynamic parameters of interface states the commonly observed anomalous behavior (e.g., frequency dispersion and capacitance hysteresis) of GaAs MIS structures can be accounted for. Results and arguments are presented indicating that these deep states are the main problem in GaAs MIS structures. Substantial decrease of their density is considered quite feasible and thus the development of GaAs MIS technology appears promising indeed.