Interface traps in InP/InAlGaAs p-n junctions by metal organic chemical vapor deposition

Abstract
We have studied the deep levels in the lattice‐matched InP/(InAlGa)As heterojunction system. Five pn junction samples were grown by metalorganic chemical vapor deposition with varied Al composition of 0%, 16%, 36%, 45%, and 55%. A vacancy‐related deep electron trap was found at the InP/(InAlGa)As interface. This trap has less concentration in the sample with higher Al composition, and is not observed when Al composition is greater than 55%. Its activation energy within the band gap increases with the increasing Al composition. The trap can be eliminated by rapid thermal annealing at 700 °C. Current‐voltage characteristics show that this trap acts as recombination centers under forward bias condition.