NUMERICAL-SIMULATION OF THE CURRENT-VOLTAGE CHARACTERISTICS OF HETEROEPITAXIAL SCHOTTKY-BARRIER DIODES

This paper presents a numerical model resulting in the current-voltage characteristics of standard and heteroepitaxial Schottky-barrier diodes. Simulations of GaAs diodes, as well as InGaAs diodes grown on GaAs and InP substrates, are presented. The model considers quantum-mechanical tunneling, and is therefore applicable to highly doped devices. A self-consistent drifted-Maxwellian distribution is used to model the electron energy distribution at high current densities. The assumption of a drifted-Maxwellian distribution is shown to lead to higher current at high bias than predicted with the assumption of a Maxwell-Boltzmann or Fermi-Dirac distribution. The presence of a heterojunction at the InGaAs-substrate interface is predicted to lead to an additional series resistance component. Good agreement is obtained between theory and experiment in both standard and heteroepitaxial Schottky diodes over a broad range of applied bias.