Low resistivity lateral P–I–N junction formed by Ni–InGaAsP alloy for carrier injection InGaAsP photonic devices

Abstract

In this study, we investigate low-resistivity InGaAsP lateral P–I–N junctions using Ni–InGaAsP alloy in conjunction with Zn diffusion. It is found that Ni–InGaAsP alloy is formed via a direct reaction between Ni and InGaAsP after annealing at more than 300 °C. The Ni–InGaAsP preserves the initial Schottky junction properties between Ni and InGaAsP, and thus exhibits an ohmic contact for n-InGaAsP and a Schottky contact for p-InGaAsP. Hence, the Ni–InGaAsP alloy can be used instead of the Si ion implantation process to form the P–I–N junction. The Ni–InGaAsP alloy exhibits significantly lower contact resistance and sheet resistance than Si implanted n+-InGaAsP. The InGaAsP lateral P–I–N junction formed with the Ni–InGaAsP alloy and Zn diffusion shows approximately 10 times lower access resistance than the n+-InGaAsP junction. Thus, we successfully achieve large on-current in the lateral P–I–N junction with the Ni–InGaAsP alloy. The fabrication procedure of the lateral P–I–N junction using the Ni–InGaAsP alloy is promising for carrier-injection photonic devices on the III–V CMOS photonics platform.