EBCMOS近贴聚焦结构及电场分布对电子运动轨迹的影响  

Influence of proximity focusing structure and electric field distribution on electron trajectory in the EBCMOS

作　　者：王巍[1,2] 李野[1] 陈卫军[1] 宋德[1] 王新[1] WANG Wei;LI Ye;CHEN Wei-jun;SONG De;WANG Xin(School of Science,Changchun University of Science and Technology,Changchun 130022,China;Division of Development Planning and Policies&Regulations,Changchun University of Technology,Changchun 130012,China)

机构地区：[1]长春理工大学理学院,吉林长春130022 [2]长春工业大学发展规划与政策法规处,吉林长春130012

出　　处：《中国光学》2020年第4期713-721,共9页Chinese Optics

基　　金：国家自然科学基金资助项目(No.11874091);吉林省科技厅重点科技研发项目(No.20180201034GX)。

摘　　要：为获得高分辨率的电子轰击型CMOS(EBCMOS)成像器件,本文就近贴聚焦结构内电场分布对电子运动轨迹的影响进行了研究。设计了不同的EBCMOS结构并得到3种电场分布情况,分别为光电阴极和背面轰击型CMOS(BSBCMOS)之间的等势面不平行、部分平行和彼此平行。根据电磁学理论结合蒙特卡洛模拟方法,分别模拟了每种电场分布情况下的电子运动轨迹。研究结果表明:当设计的电子倍增层表面覆盖一层30 nm的超薄重掺杂层,保持极间电压为4000 V且极间距为1 mm时,光生电子轰击BSB-CMOS表面时扩散直径可减小至30μm。此结构具有电子聚焦作用,有助于实现高分辨率的EBCMOS。同时,进一步研究了光电阴极与BSB-CMOS之间的距离和电压对电子扩散直径的影响。研究发现,近贴间距越小、加速电压越高,相应的电场强度就越高,越有利于电子聚焦。本文工作将为改进电子轰击型CMOS成像器件的分辨率特性提供理论指导。In order to obtain high-resolution Electron Bombarded CMOS(EBCMOS)imaging devices,we study the effect of electric field distribution on the electron trajectory in proximity focusing EBCMOS devices.Three different electric field distributions are obtained by designing different EBCOMS structure,namely,the nonparallel,partially parallel,and parallel equipotential surfaces between the photocathode and the Back-side Bombarded CMOS(BSB-CMOS).The electron trajectories in each case are simulated according to electromagnetism theory and monte carlo simulation method.The results indicate that,when the BSBCMOS is bombarded by photoelectrons,the scattering diameter can be reduced to 30μm under the condition that the surface of the electron multiplying layer is covered with 30 nm ultra-thin heavily doping layer and the voltage between electrodes is maintained at 4000 V while the distance between photocathode and BSBCMOS is 1 mm.This structure is helpful to realize electrons focusing and achieve EBCMOS with high resolution.Then,the influence of the distance and voltage between the photocathode and BSB-CMOS on scattering diameter is studied.The results indicate that the electric field strength increases with the decrease of proximity distance and the increase of the acceleration voltage.This work will provide theoretical guidance for improving the resolution characteristics of EBCMOS imaging devices.

关 键 词：微光像增强器 电子轰击成像 近贴聚焦结构 EBCMOS 

分 类 号：TN223[电子电信—物理电子学]