Numerical modeling of noise in gallium arsenide semiconductor devices using the Monte Carlo method

A Monte Carlo technique for the calculation of noise in unipolar GaAs semiconductor devices is developed. The model is based on the Shockley-Ramo theorem, which allows the instantaneous current at the terminals of a device to be calculated as a function of time. Once the instantaneous current is found, the current autocorrelation function and spectral density can be found. Results using this method for the case of homogeneous samples are compared with experiment. Both Nyquist and hot electron noise are demonstrated. A boundary condition suitable for use in devices of submicron dimensions is developed, and applied to resistors from 0.5 to 1.5 $\mu$m in length. A method for conducting a full-device Monte Carlo simulation of a Schottky Barrier diode is developed. The noise is simulated in two diodes, one with a 0.12 and the other with a 1.0 $\mu$m epilayer, and except when shot noise dominates the results are shown to compare quite favorably with experiment. A second method, a particle crossing method, is shown to be useful for calculating shot noise