一种低暗计数率P-I-N结构的单光子雪崩二极管探测器  

A P-I-N Structure Single-Photon Avalanche Diode Detector with Low Dark Count Rate

作　　者：李峥 刘丹璐 董杰 卞大井 徐跃[1,2] Li Zheng;Liu Danlu;Dong Jie;Bian Dajing;Xu Yue(College of Integrated Circuit Science and Engineering,Nanjing University of Posts and Telecommunications,Nanjing 210023,Jiangsu,China;National and Local Joint Engineering Laboratory of RF Integration&Micro-Assembly Technology,Nanjing 210023,Jiangsu,China)

机构地区：[1]南京邮电大学集成电路科学与工程学院,江苏南京210023 [2]射频集成与微组装技术国家地方联合实验室,江苏南京210023

出　　处：《光学学报》2024年第9期25-30,共6页Acta Optica Sinica

基　　金：国家自然科学基金(62171233);核探测与核电子学国家重点实验室资助项目(SKLPDE-KF-202307)。

摘　　要：基于180 nm BCD工艺制备出一种P型注入增强型P-I-N结构的单光子雪崩二极管(SPAD)探测器。采用P型漂移区与高压N+埋层之间的低掺杂浓度P型外延层作为I层深结雪崩区,提高了近红外波段的光子探测概率(PDP)。利用低掺杂浓度的P型外延层作为虚拟保护环,防止了器件横向击穿,降低了暗计数率(DCR)。测试结果表明,虚拟保护环宽度(GRW)为5μm时,器件雪崩电压为56 V。在5 V过偏压下600 nm处的峰值PDP为41%,在901 nm的近红外波段下PDP大于6%,DCR为0.56 s^(-1)·μm^(-2),后脉冲率小于1.2%,表现出良好的电学和光学特性。所提出的SPAD器件为硅基高灵敏度近红外单光子探测器设计提供了一种可选的解决方案。Objective Over the past few decades,single-photon detection technology has rapidly developed.Single-photon avalanche diode(SPAD)detectors operating in Geiger mode have advantages such as high sensitivity,fast response speed,and strong capability for single-photon detection.As a result,they have been widely used in optical sensing fields such as quantum communication,lidar,and fluorescence lifetime imaging.SPAD arrays compatible with CMOS technology have gained significant attention due to their high integration and miniaturization.In laser radar applications,SPADs are employed to receive returning photons.However,optical signals are susceptible to environmental factors like dust and weather conditions.The received light intensity might be at the single-photon level,and high dark count noise can degrade device performance.Considering the potential harm of short-wavelength lasers to human eyes,the design of SPAD devices with low dark counts and high photon detection probabilities has become a hot research direction.Methods The SPAD(Fig.1)employs a P-I-N diode structure,with the avalanche region located between the P-type drift region and the high-voltage N+buried layer.The P epitaxial layer serves as the intrinsic region,with P-trap guard rings and virtual guard rings surrounding the P-doped region to mitigate the impact of shallow trench isolation on dark count rates(DCR).The proposed SPAD devices with GRW of 3,4,5μm are simulated based on 0.18μm BCD technology to study the impact of GRW on device performance[Fig.2(a)].Simulation results show that the device can only work normally at GRW of 5μm without a large edge electric field,and it will also cause the dark count to decrease.Figure 2(c)illustrates the 2D electric field distributions when STI extends into PW.Changing STI appropriately can hardly improve the electric field strength.Results and Discussions The I-V characteristic of the SPAD is firstly measured which exhibits avalanche breakdown voltage at around 56 V[Fig.3(c)],showing no difference to the TCAD

关 键 词：探测器 单光子雪崩二极管(SPAD) P-I-N结构 光子探测概率(PDP) 暗计数率(DCR) 

分 类 号：TN491[电子电信—微电子学与固体电子学]