Abstract
We present Monte Carlo simulations of impact-ionization-induced impurity breakdown in n-GaAs at 4.2 K with dopants arranged in parallel monoatomic planes (δ doping). ssS-shaped current-field characteristics are obtained by a direct single-particle Monte Carlo simulation for homogeneously doped material. For δ-doped GaAs we calculate the spatial distribution of the carrier density, mean electron energy, and space-charge field self-consistently as a function of time by a weighted ensemble Monte Carlo method. For initial values on the low-conductivity branch of the ssS-shaped characteristics we find that current filaments centered around the δ-doped layers are formed. Our simulations explain the experimentally observed shrinking of the bistable regime as well as its shift to lower voltages as compared to homogeneous material.
- Received 18 October 1994
DOI:https://doi.org/10.1103/PhysRevB.51.7725
©1995 American Physical Society