Collection efficiency and charge transfer optimization for a 4-T pixel with multi n-type implants

作     者：李伟平 徐江涛 徐超 李斌桥 姚素英 

作者机构：School of Electronic and Information EngineeringTianjin University 

出 版 物：《Journal of Semiconductors》 (半导体学报（英文版）)

年 卷 期：2011年第32卷第12期

页      面：91-94页

核心收录：

学科分类：08[工学] 0803[工学-光学工程] 

基　　金：Project supported by the National Natural Science Foundation of China(Nos.61036004 60976030) 

主　　题：CMOS image sensor photodiode collection efficiency charge transfer image lag 

摘      要：In order to increase collection efficiency and eliminate image lag, multi n-type implants were introduced into the process of a pinned-photodiode. For the purpose of improving the collection efficiency, multi n-type implants with different implant energies were proposed, which expanded the vertical collection region. To reduce the image lag, a horizontal gradient doping concentration eliminating the potential barrier was also formed by multi n-type implants. The simulation result shows that the collection efficiency can be improved by about 10% in the long wavelength range and the density of the residual charge is reduced from 2.59 × 10^9 to 2.62 × 10^7 cm^-3.