Quasistatic capacitance-voltage characteristics of plane-parallel structures:: Metal/semi-insulator/metal

Quasistatic capacitance-voltage characteristics of plane-parallel structures of the semi-insulating GaAs with two metal contacts are calculated numerically. The model of residual shallow acceptors compensated for by an excess of deep donors is used for the semi-insulating GaAs. Under consideration is the relaxation regime for the charge transport in the semi-insulator. We analyze metal/semi-insulator/metal structures for various parameters of the metal contacts and of the semi-insulator. It is shown that a negative capacitance can be obtained in some cases. A more detailed analysis is performed for the following structure: p-type like metal contact/n-type semi-insulator/n-type like metal contact. (C) 2000 American Institute of Physics. [S0021- 8979(00)01516-4].