LINEAR AND NONLINEAR-ANALYSIS OF MICROWAVE-POWER GENERATION IN SUBMICROMETER N(+)NN(+)INP DIODES

A closed hydrodynamic model and the associated numerical procedures ar e developed for simulating hot-carrier transport in submicron semicond uctor devices. To check the validity of the model, the steady-state ch aracteristics of near-micron n(+)nn(+) InP diodes are compared with a standard Monte Carlo approach. The excellent agreement found fully val idates the physical reliability of our model which has been further de veloped to investigate linear and nonlinear time-dependent characteris tics. The contribution of each part of the device, when operating as m icrowave power-generation, is analyzed through the spatial profiles of the impedance-field spectrum. The usual subdivision of the n-region i nto a passive (dead-zone) and active zone is carried out. The dead zon e is found to manifest itself as a purely real resistance which is pra ctically independent of the frequency. One or more spatial zones which are responsible for the generation are shown to be formed in the acti ve region of the diode. By reducing the length of the n-region, under the condition that the total current is constant in time, the additivi ty of the contributions from each part of the device into the generati on spectrum is proven. The predictions of the linear analysis are comp ared with a direct simulation of the diode performance in the external resonant circuit. A wide-band tuning of the generation frequency from 100 up to 200 GHz is demonstrated. The microwave power generation is shown by both hydrodynamic and Monte Carlo simulation to be caused by the formation and propagation through the diode of accumulation layers . Theoretical results are found to compare well with available experim ents.