In_(0.53)Ga_(0.47)As/InP高速光电二极管材料生长及光电性能

In_(0.53)Ga_(0.47)As/InP High Speed Photodiode Material Growth and Opto-electric Characterization

利用低压MOCVD技术制备PIN结构的InP基InGaAs外延材料。采用分层吸收渐变电荷倍增(SAGCM)结构,通过两次Zn扩散、多层介质膜淀积、Au/Zn p型欧姆接触、Au/Ge/Ni n型欧姆接触等标准半导体平面工艺,设计制造正入射平面In_(0.53)Ga_(0.47)As/InP雪崩光电二极管器件。该器件采用与InP衬底晶格匹配的In_(0.53)Ga_(0.47)As材料做吸收层,InP材料做倍增层,同时引入InGaAsP梯度层。探测器件光敏面直径50μm,器件测试结果表明该器件光响应特性正常,击穿电压约43 V,在低于击穿电压3 V左右可以得到大约10 A/W的光响应度,在0 V到小于击穿电压1 V的偏压范围内,暗电流只有1 nA左右。光电二极管在8 GHz以下有平坦的增益,适用于5 Gbit/s光通信系统。

InP based InGaAs epitaxial material with PIN structure was grown by low pressure-MOCVD technology. Using separated absorption, grading, charge, and multiplication(SAGCM) structures and standard semiconductor planar processes such as twice Zn diffusion, multi-layer dielectric film deposition, p-type ohmic contacts by Au/Zn and n-type ohmic contacts by Au/Ge/Ni,etc., the normal incidence plane In0.53Ga0.47As/InP avalanche photodiode device was designed and fabricated. In0.53Ga0.47As material was used as the absorption layer of the device which was lattice-matched with InP substrate, InP material was used as the multiplication layer, at the same time, InGaAsP was introduced as gradient layer. The diameter of the device optical window is 50 μm, the device test results show that the light response characteristics of the device are normal. The device has breakdown voltage of 43 V, photoresponse of about 10 A/W with a bias of 3 V lower than the breakdown voltage, and dark currents of about 1 nA with bias voltage range of 0 V to 1 V less than breakdown voltage. The photodiode has a flat gain under 8 GHz and it is applicable to 5 Gbit/s optical communication system.