BCD工艺下光电集成的单光子雪崩光电二极管及前端电路的研制  

Development of photoelectric integrated single photon avalanche photodiode and front-end circuit based on BCD technology

作　　者：史晓凤 庞雪 朱丽君 张新宇 张媛 韩波 李佩君 郭博 程翔 SHI Xiao-feng;PANG Xue;ZHU Li-jun;ZHANG Xin-yu;ZHANG Yuan;HAN Bo;LI Pei-jun;GUO Bo;CHENG Xiang(School of Computer and Information Engineering,Fuyang Normal University,Fuyang 236037,China;School of Aerospace Engineering,Xiamen University,Xiamen 361102,China)

机构地区：[1]阜阳师范大学计算机与信息工程院,安徽阜阳236037 [2]厦门大学航空航天学院,福建厦门361102

出　　处：《光学精密工程》2021年第2期267-277,共11页Optics and Precision Engineering

基　　金：安徽省自然科学基金资助项目(No.1608085QF159,No.1808085QF209,No.2008085MF215);安徽省高校自然科学研究重点项目(No.KJ2017A333,No.KJ2020A0536);中央高校基本科研业务费专项资金资助(Nos.207201700516,20720160016);阜阳师范大学自然科学重点项目(No.2018FSKJ01ZD,No.2020FSKJ05ZD);阜阳师范大学一般项目(No.2019FSKJ09);阜阳市横向项目(No.XDHX2016005);无锡商业化基金(No.CBE01G1748)。

摘　　要：提出一种基于BCD工艺用于检测微弱光信号的单光子雪崩光电二极管(SPAD)及前端淬灭-复位电路(QRC)。为减小边缘击穿的风险,提高响应度,设计了一种圆形P+/Nwell/Deep Nwell结构SPAD,Deep Nwell和衬底之间形成的pn结,能够有效减少p衬底流向雪崩区的暗电流,降低暗计数率,也保证了较小的纵向渡越时间,提高了响应速度。同时设计了P阱保护环,增大了器件的击穿电压。采用silvaco对器件进行二维仿真,与传统的P+/Nwell结构以及P+/Nwell/BNwell结构进行了比较,验证了设计结构在击穿电压、响应度方面的优越性。为实现光电探测器与集成电路的协同设计,改进了APD光电器件的等效电路模型并在此基础上设计了主动淬灭复位电路,死时间约为2.6 ns,能够达到快速探测的目的。测试结果表明,P+/Nwell/DNwell结构的雪崩击穿电压为15.8 V,在过电压为0.2 V时,650 nm光照射下,响应度约为0.80 A/W,暗计数率为20 kHz。A type of single-photon avalanche photodiode(SPAD)and front-end quench reset circuit(QRC),based on bipolar-CMOS-DMOS(BCD)technology,for detecting weak optical signals was proposed in this study.To reduce the risk of edge breakdown and to improve the responsivity,a circular SPAD with a P+/Nwell/deep-Nwell(DNwell)structure was designed.The pn junction formed between the DNwell and substrate could effectively reduce the dark current flowing from the P substrate to the avalanche region.It could also reduce the dark count rate,ensure a small longitudinal transit time,and improve the response speed.Simultaneously,a Pwell protection ring was designed to increase the breakdown voltage of the device.A two-dimensional simulation of the device was conducted using SILVACO,and the proposed structure was then compared with the traditional P+/Nwell and P+/Nwell/DNwell structures.The advantages of the design structure in terms of breakdown voltage and responsivity were verified.To realize a cooperative design of photodetectors and integrated circuits,the equivalent circuit model of avalanche photodiode optoelectronic devices was improved.Accordingly,an active quenching reset circuit was designed.The dead time is determined to be approximately 2.6 ns,which can achieve the purpose of rapid detection.Results show that the avalanche breakdown voltage of the P+/Nwell/DNwell structure is 15.8 V.When the excess bias voltage is 0.2 V,the responsivity is approximately 0.80 A/W,and the dark count rate is 20 kHz.

关 键 词：单光子雪崩光电二极管 光电集成 BCD工艺 响应度 飞行时间传感器 

分 类 号：TN451[电子电信—微电子学与固体电子学] TP212.1[自动化与计算机技术—检测技术与自动化装置]