A DEGENERATELY-DOPED GAAS SCHOTTKY DIODE MODEL APPLICABLE FOR TERAHERTZ FREQUENCY REGIME OPERATION

This paper investigates the physics and operation of GaAs Schottky dio des within the terahertz frequency regime, Specifically, electron scat tering and transport models are developed for the degenerately doped c onditions necessary for very-high-frequency diode operation. This stud y incorporates the physical effects of electron-electron scattering an d degenerate electron statistics into the scattering models for ionize d impurities and polar optical phonons, These derivations are then use d to arrive at analytical mobility models for transport in degenerate GaAs bulk regions. This work also derives improved expressions for the rmionic and field emission within degenerate Schottky barrier structur es. These emission models are then combined with a momentum-balance de scription of electron transport in the bulk region to model the dynami c operation of the diode, Numerical simulation results are presented t o illustrate the roles played by thermal emission over the barrier and field (tunneling) emission through the barrier on diode operation at terahertz frequencies. These results clearly demonstrate the strong in fluence that doping has on the emission currents within heavily doped Schottky diodes.