电子辐照对4H-SiC MOS材料缺陷的影响

Effects of Electron Irradiation on Defects of 4H-SiC MOS Materials

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摘要 4H-SiC金属氧化物半导体(MOS)基器件在电子辐照环境下应用时可能产生新的材料缺陷,导致其电学性能发生退化。本文选取结构最简单的MOS基器件(4H-SiC MOS电容器)为对象,研究了一系列电子辐照剂量下材料缺陷的演变情况。在10 MeV电子束下对MOS样品进行30、50、100、500、1 000 kGy剂量的辐照,对辐照前、后样品进行深能级瞬态谱测试(DLTS)和电容-电压(C-V)曲线表征。DLTS实验结果表明,低剂量电子辐照前、后4H-SiC/SiO_(2)界面及近界面处的缺陷没有发生明显变化,而高剂量辐照导致双碳间隙原子缺陷的构型发生了改变,演变后的构型能级位置更深,化学结构更加稳定。C-V曲线测试结果发现,不同电子辐照剂量导致MOS电容器平带电压发生不同程度的负向漂移,这很可能是SiO_(2)氧化层中氧空位数量和4H-SiC/SiO_(2)界面及近界面处缺陷数量共同影响的结果。本文研究结果对研发和优化抗电子辐照的4H-SiC MOS制备工艺具有一定的参考价值。 4H-SiC metal-oxide-semiconductor(MOS)-based devices appear to worse electrical performance when exposed to electron irradiation,owing to the production of material defects.This study demonstrates an analysis of defect evolution of 4H-SiC MOS capacitors with the simplest structure,subjected to a series dose of electron irradiation with 10 MeV electron beam,including 30,50,100,500,1000 kGy.Deep level transient spectroscopy(DLTS)test and capacitance-voltage(C-V)measurement were used to obtain defects information among MOS samples pre-and post-irradiation.DLTS results present that a low dose of irradiation causes no evident impact on defect evolution near and at the 4H-SiC/SiO_(2) interface,whereas a high dose of irradiation makes a defect configuration of carbon interstitial dimer defect evolve into another more stable one at a deeper energy level.C-V curves show that different irradiation doses lead to different negative shift degrees of flat-band voltage.This is considered to be resulted from multiple factors,including oxygen vacancies in the SiO_(2) layer and defects near and at the 4H-SiC/SiO_(2) interface.This work might be helpful for the development and optimization of 4H-SiC MOS fabrication with respect to anti-irradiation performance.

作者刘帅熊慧凡杨霞杨德仁皮孝东宋立辉 LIU Shuai;XIONG Huifan;YANG Xia;YANG Deren;PI Xiaodong;SONG Lihui(State Key Laboratory of Silicon and Advanced Semiconductor Materials,School of Materials Science and Engineering,Zhejiang University,Hangzhou 310027,China;Institute of Advanced Semiconductors&Zhejiang Provincial Key Laboratory of Power Semiconductor Materials and Devices,ZJU-Hangzhou Global Scientific and Technological Innovation Center,Hangzhou 311200,China;College of Materials&Environmental Engineering,Hangzhou Dianzi University,Hangzhou 310018,China)

机构地区浙江大学材料科学与工程学院浙江大学杭州国际科创中心杭州电子科技大学材料与环境工程学院

出处《人工晶体学报》 CAS 北大核心 2024年第9期1536-1541,共6页 Journal of Synthetic Crystals

基金浙江大学杭州国际科创中心人才专项。

关键词 4H-SiC MOS 电子辐照缺陷变化双碳间隙原子深能级瞬态谱 4H-SiC MOS electron irradiation defect evolution carbon interstitial dimer deep level transient spectroscopy

分类号 TN386.1 [电子电信—物理电子学]