基于近弹道优化的方法提出了一种高性能的单行载流子光电二极管(UTC-PD)的设计方案,用该方案制备的UTC-PD具有大的响应速度、响应度和饱和输出,且可减轻负载电压摆幅效应。设计的新光电二极管采用具有渐变掺杂的部分耗尽吸收层。在收集层底部插入p型掺杂薄电荷层,对器件内部电场进行了优化设计,让光生电子以过冲速度漂移,这样可减少电子的渡越时间,并使器件具备了高偏置电压操作能力,从而增大3 dB带宽,提升饱和性能。仿真分析表明,在8 V的高反向偏置电压条件下,有源区面积为16 μm 2的该器件可以获得超过86 GHz的3 dB带宽,响应度为0.17 A/W。

Based on the nearly-ballistic optimization method, a high performance uni-traveling-carrier photodiode (UTC-PD) design scheme is proposed in this paper. The UTC-PD prepared by this scheme has high response speed, high responsivity, and large saturation output, and can alleviate the load voltage swing effect. The designed novel photodiode uses a partially depleted absorption layer with gradient doping. A thin p-type doped charge layer is inserted at the bottom of the collection layer. The internal electric field of the device is optimized to make the photogenerated electrons drift at the overshoot speed, reduce the electron transit time, make the device have high bias voltage operation ability, and therefore increase the 3 dB bandwidth and improve the saturation performance. Simulation results show that under the condition of high reverse bias voltage of 8 V, the device with an active area of 16 μm 2 can obtain a 3 dB bandwidth exceeding 86 GHz with a responsivity of 0.17 A/W.