Comparison of Excess Noise in InAlAs and AlGaAs Digital and Random Alloy Avalanche Photodiodes

Abstract

Digital alloy In 0.52 Al 0.48 As avalanche photodiodes exhibit lower excess noise than those fabricated from random alloys. This paper compares the temperature dependence, from 203 K to 323K, of the impact ionization characteristics of In 0.52 Al 0.48 As and Al 0.74 Ga 0.26 As digital and random alloys. These results provide insight into the low excess noise exhibited by some digital alloy materials, and these materials can even obtain lower excess noise at low temperature.