Si基PIN光电探测器电场隔离结构对暗电流的影响

对Si基PIN光电探测器的电场隔离结构进行了研究,讨论了电场隔离结构的作用以及其与暗电流的关系,并进行了仿真模拟与测试分析。电场隔离结构主要将有源区和边缘隔离从而降低暗电流,结合仿真模拟结果和实验测试结果,分析得到电场隔离结构主要降低与周长有关的暗电流,对于小尺寸器件作用更明显。

Scalability of dark current in silicon PIN photodiode

The mechanism for electrical conduction is investigated by the dark temperature-dependent current–voltage characteristics of Si PIN photodiodes with different photosensitive areas.The characteristic tunneling energy E（00） can be obtained to be 1.40 me V,1.53 me V,1.74 me V,1.87 me V,and 2.01 me V,respectively,for the photodiodes with L = 0.25 mm,0.5 mm,1 mm,1.5 mm,and 2 mm by fitting the ideality factor n versus temperature curves according to the tunneling-enhanced recombination mechanism.The trap-assisted tunneling-enhanced recombination in the i-layer plays an important role in our device,which is consistent with the experimental result that area-dependent leakage current is dominant with the side length larger than 1 mm of the photosensitive area.Our results reveal that the quality of the bulk material plays an important role in the electrical conduction mechanism of the devices with the side length larger than 1 mm of the photosensitive area.

基于SOI衬底和外延衬底的高速光电探测器研究

高速硅基光电探测器价格低廉且易于和光接收机集成,在短距离光通信中被广泛应用。对基于绝缘硅(SOI)和外延(EPI)两种不同衬底的互补金属氧化物(CMOS)工艺的光电探测器进行了理论模拟和实验研究,理论模拟和实验规律一致。实验表明,研制的基于SOI衬底的光电探测器的小信号带宽最高为205MHz,响应度为0.051A/W;基于EPI衬底的光电探测器在相同条件下最高带宽为131MHz,响应度为0.21A/W。