高速InP/InGaAs雪崩光电二极管

High speed InP/InGaAs avalanche photodiode

采用分层吸收渐变电荷倍增(SAGCM)结构,通过两次扩散、多层介质淀积、AuZn p 型欧姆接触、AuGeNi n 型欧姆接触等工艺,设计制造了正面入射平面 InP/InGaAs 雪崩光电二极管,器件利用 InGaAs做吸收层,InP 做增益层,光敏面直径50μm;测试结果表明器件有正常的光响应特性,击穿电压32～42 V,在低于击穿电压2 V 左右可以得到大约10 A/W 的光响应度,在0到小于击穿电压1 V 的偏压范围内,暗电流只有1 nA 左右;器件在2.7 GHz 以下有平坦的增益。

The avalanche photodiodes with separated absorption,grading,charge,and multiplication (SAGCM) structures through the two-proliferation,multiplayer dielectric deposition.Using InGaAs and InP as absorption layer and multiplication layer respectively,the devices are processed by double diffusion,multi-layer dielectric,p-type Ohmic contacts by AuZn and n-type Ohmic contacts by AuGeNi.The diameter of the optical window of APD is 50 μm.The devices have breakdown voltages of 32～42 V and dark currents of about 1 nA with bias in 0 to less than 1 V breakdown point.Normal optical response is performed and a responsivity of about 10 A/W is obtained with a bias of 2 V low than the breakdown voltage.The APDs demonstrate planar gain under 2.7 GHz.