Effect of Dead Space on Low-Field Avalanche Multiplication in InP

A systematic study of avalanche multiplication behavior in InP has been performed on a series of diodes with avalanche region widths w ranging from 2.50 to 0.08 mum. The local model for impact ionization is found to increasingly overestimate the multiplication at low electric fields as w decreases due to the presence of dead space. The suppression of the multiplication can be modeled accurately by applying a simple correction for the injected carrier dead space to the local model, which enables the multiplication to be accurately predicted over a wide range of avalanche region widths.