Design of CMOS active pixels based on finger-shaped PPD  

作　　者：Feng Li Ruishuo Wang Liqiang Han Jiangtao Xu 

机构地区：[1]Tianjin Key Laboratory of Imaging and Sensing Microelectronic Technology,School of Microelectronics,Tianjin University,Tianjin 300072,China [2]Electronic Instrumentation Laboratory,Delft University of Technology,Delft 2628CD,Netherlands

出　　处：《Journal of Semiconductors》2020年第10期38-44,共7页半导体学报（英文版）

基　　金：supported by the Tianjin Key Laboratory of Imaging and Sensing Microelectronic Technology。

摘　　要：To improve the full-well capacity and linear dynamic range of CMOS image sensor,a special finger-shaped pinned photodiode(PPD)is designed.In terms of process,the first N-type ion implantation of the PPD N buried layer is extended under the transfer gate,thereby increasing the PPD capacitance.Based on TCAD simulation,the width and spacing of PPD were precisely adjusted.A high full-well capacity pixel design with a pixel size of 6×6μm^2 is realized based on the 0.18μm CMOS process.The simulation results indicate that the pixel with the above structure and process has a depletion depth of 2.8μm and a charge transfer efficiency of 100%.The measurement results of the test chip show that the full-well capacity can reach 68650 e–.Compared with the conventional structure,the proposed PPD structure can effectively improve the full well capacity of the pixel.

关 键 词：CMOS active pixel full well capacity full depletion 

分 类 号：TP212[自动化与计算机技术—检测技术与自动化装置]