Impact ionization experiments on compound semiconductors

Impact ionization coefficients are important parameters for the understanding of high field transport in semiconductors. In this paper we review the experimental determination of impact ionization coefficients. We begin by briefly describing the impact ionization process and its importance in device applications. The basic relationships between the impact ionization coefficients and the performance of avalanche photodiode (APDs) are explained. Following this, the experimental requirements for the accurate determination of the ionization coefficients are presented. The results of a few specific experiments on impact ionization for III-V semiconductors are then reviewed.