高速大像素CMOS图像传感器中钳位光电二极管形状设计的研究进展  

Research Progress of Pinned Photodiode Shape Design for High Speed Large Pixel CMOS Image Sensor

作　　者：张文轩 程正喜[1] Zhang Wenxuan;Cheng Zhengxi(Shanghai Institute of Technical Physics,Chinese Academy of Sciences,Shanghai 200083,China)

机构地区：[1]中国科学院上海技术物理研究所,上海200083

出　　处：《半导体技术》2024年第6期514-523,共10页Semiconductor Technology

摘　　要：采用钳位光电二极管(PPD)的CMOS图像传感器,由于其优异的性能,已成为图像传感领域中占主导地位的技术。然而,更大尺寸PPD的应用在电荷传输速度和效率方面存在挑战,特别是在微光、高速探测的场景中,传统的像素设计难以满足必要的性能标准。一种有效的方法是通过PPD的形状设计来提升大像素性能。首先全面概述了产生PPD横向电场的两种机制:边缘电场设计和钳位电压调制,并探讨了基于这两种设计策略的各种设计改进。然后总结了传输栅-浮空扩散(TG-FD)节点收集结构及像素整体布局优化的相关研究进展。此外,还研究了PPD的形状设计对暗电流的影响。通过全面分析PPD形状设计中采用的方法,为提升大像素设计提供了参考。CMOS image sensors featuring pinned photodiodes(PPDs) have emerged as the predominant technology in image sensing field owing to their exceptional performance.Nonetheless, the application of larger PPDs presents challenges in charge transfer speed and efficiency, especially in low-light, high-speed detection scenarios where conventional pixel configurations struggle to meet the requisite performance standards.The shape design of PPDs is considered as an effective way to enhance the large pixel performance.Firstly, two mechanisms for generating PPD lateral electric fields are comprehensively overviewed, including edge electric field design and clamp voltage modulation, and various design improvements based on these two design strategies are discussed.Then, the related research progress of the overall layout optimization for the transfer gate-floating diffusion(TG-FD) nodes collection structure and the pixel are summarized.Moreover, the influence of the shape design of the PPD on dark current is investigated.The comprehensive analysis of the methods used in PPD shape design provides reference for enhancing large pixel designs.

关 键 词：CMOS图像传感器 大尺寸像素 横向电场 电荷转移 暗电流 

分 类 号：TN364.2[电子电信—物理电子学] TP212[自动化与计算机技术—检测技术与自动化装置]