Dual pin photodetector with very low parasitic series interconnection

摘要

back-illuminated photodetector for balanced coherent receivers applications is presented. The photodetectors have an InP/InGaAs/InP p-i-n structure. Several additional semiconductor layers have been added to fabricate the structure by selective wet etching. The material was grown by metalorganic vapor phase epitaxy (MOVPE) on a semiinsulating, Fe doped, InP substrate. The passivation and the insulation between contacts were obtained using polyimide. The contact structure is intended to connect the photodetector to the package by flip-chip. The measured photodetector capacitance was around 0.2 pF for a single photodetector (without series connection), the series resistance under 20 ohms, and the dark current under 10 nA.