单晶硅表面钝化层在低能电子辐照前后的SIMS和XPS分析  

SIMS and XPS Analysis of Interfaces in Passivation Layers on C-Silicon Under Low-Energy Electron Radiation

作　　者：杨玉青[1] 雷轶松 向勇军 李刚 熊晓玲[1] 徐建[1] 董文丽[1] YANG Yu-qing;LEI Yi-song;XIANG Yong-jun;LI Gang;XIONG Xiao-ling;XU Jian;DONG Wen-li(Institute of Nuclear Physics and Chemistry,China Academy of Engineering Physics,Mianyang 621900,China;No.44 Institute of China Electronics Technology Group Corporation,Chongqing 400060,China)

机构地区：[1]中国工程物理研究院核物理与化学研究所,四川绵阳621900 [2]中国电子科技集团第44研究所,重庆400060

出　　处：《核化学与放射化学》2021年第1期74-80,I0003,共8页Journal of Nuclear and Radiochemistry

基　　金：国家自然科学基金资助项目(11575161;11605167)。

摘　　要：为了研究低能电子辐照对单晶硅器件表面钝化材料中产生的化学微结构的变化,在轻掺杂P型单晶硅基底上制作了三种表面钝化膜,分别是单一SiO2钝化膜、SiO2/Si3N4复合钝化膜、硼硅玻璃/Si3N4复合钝化膜,开展了表面钝化单晶硅在最大能量70 keV的加速器电子束下的辐照实验。样品在空气气氛下辐照6 h,用二次离子质谱(SIMS)测试了辐照前后三种表面钝化膜中Si、N、B的纵深变化,同时用Ar离子刻蚀X射线表面光电子能谱(XPS)对Si元素的化学结合状态进行测试分析。结果表明:对单一SiO2钝化的轻掺杂P型材料,辐照在SiO2/Si界面产生明显的材料结构变化,界面附近的SiO2不再是完整化学计量比,而是SiOx(x<2);对SiO2/Si3N4复合钝化的轻掺杂P型材料,辐照对SiO2/Si3N4界面结构影响较小,主要的影响仍然在SiO2/Si界面,SiO2辐照分解后产生的游离O元素可扩散到SiO2/Si3N4界面;辐照在硼硅玻璃/Si界面和硼硅玻璃/Si 3N 4界面引起的变化小于在SiO2/Si界面和SiO2/Si3N4界面的变化。研究表明低能电子辐照对单晶硅表面钝化层的化学微结构损伤主要存在于SiO 2/Si界面,该结构损伤并不能通过SiO2/Si3N4复合钝化得到明显改善,而采用硼硅玻璃/Si 3N 4复合钝化有助于增强单晶硅表面及钝化层各界面材料结构的稳定性。In order to investigate chemical structure change in surface passivation layers of C-silicon material under radiation of low-energy electrons,three kinds of surface passivation C-silicon material are prepared,which are mono-SiO2 layer,SiO2/Si3N4 compound layers and boronsilicate glass/Si3N4 compound layers.They are radiated under electrons of Emax=70 keV from electron accelerator for 6 hours in air atmosphere.Depth changes of Si,N,B before and after electron radiation are measured by secondary ion mass spectroscopy(SIMS)and argon ion etching X-ray photoelectron spectroscopy(XPS).The results show that changes at interfaces of SiO2/Si are remarkable both in mono-SiO2 passivation samples and Si3N4/SiO2 passivation samples.The possible reason is stoichiometric proportion of SiO2 at the interface is changed to SiOx(x<2)under irradiation because of Si-O bond breaking.In case of Si3N4/SiO2/Si passivation sample,the dissociated oxygen results from Si-O bond breaking might drift through SiO2 to SiO2/Si3N4 interface.In case of Si3N4/boronsilicate glass/Si sample,chemical structure changes in interfaces of boronsilicate glass/Si 3N 4 and boronsilicate glass/Si are less remarkable than those both of SiO2/Si and Si3N4/SiO2/Si samples.It indicates that the radiation damage of surface passivation layers of C-silicon material from low-energy electrons mainly takes place at interface of SiO2/Si,which can not be noticeably improved by SiO2/Si3N4 combined passivation.While using boronsilicate glass/Si 3N 4 combined passivation can help to keep chemical structure stable at interfaces between surface passivation layers of C-silicon material under radiation of low-energy electrons in air atmosphere.

关 键 词：表面钝化 低能电子辐照 SIMS XPS β辐伏同位素电池 

分 类 号：O649.2[理学—物理化学]