Analysis and simulation of domain propagation in non-uniformly doped bulk GaAs

Exploitation of bulk phenomena permits the realization of complex electronic functions with single bulk structures. In particular, devices with appropriately designed conduction profiles are capable of such operations as binary word generation, pulse width modulation, and DC to frequency conversion. This paper addresses itself to the behavior of high field domains in nonuniformly doped samples of n-type GaAs. A mathematical analysis of stable domain propagation is undertaken for such devices, culminating in a simple graphical technique for predicting their operation in resistive bias networks. The graphical analysis requires only a knowledge of the device doping profile and a family of material characteristics representing the product of donor density and outside electric field as a function of domain excess voltage for doping densities in the range of interest.