Capacitance-voltage characteristic of anisotype heterojunction in the presence of interface states and series resistance

The capacitance-voltage characteristics of an anisotype heterojunction have been studied considering the presence of interface states and series resis tance. The dependence of the above characteristics on the interface state d ensity, doping concentration, temperature and series resistance has been ev aluated, It is shown that the functional dependence of the device capacitan ce is generally determined by the surface potentials on the two sides of th e junction. The value of the diffusion potential obtained under the limitin g case of low interface state density and series resistance has been found about 0.1 V less compared to the experimental result of Unlu et al. [Appl, Phys, Lett. 56 (1990) 842]. This discrepancy can possibly be attributed to the effect of frequency on the device capacitance, (C) 2001 Elsevier Scienc e B.V. All rights reserved.