6H-SiC氧化层中Na离子的C-V测试研究  

Study on C-V Measurement of Na^+ Ion in 6H-SiC Oxide

作　　者：牟维兵[1,2] 龚敏[2] 曹群[2] 

机构地区：[1]中国工程物理研究院电子工程研究所,四川绵阳621900 [2]四川大学物理学院,成都610064

出　　处：《微电子学》2010年第5期762-764,共3页Microelectronics

摘　　要：半导体热氧化过程中,不可避免会沾污Na离子,造成MOS电容的C-V曲线平带电压漂移。在1 200℃下热氧化,生成SiC/SiO2界面,进而制作MOS电容。采用高电压偏置,在高温度条件下作用于MOS电容;利用Keithley590C-V分析仪,测量其C-V曲线。计算出氧化层Na离子密度为2.26×1012/cm2,高温负高压偏置不能完全恢复MOS电容的C-V特性,且高压偏置处理后的MOS电容在积累区的电容值减小,与Si材料MOS的情况不同。主要原因是SiC氧化层和界面质量较差,在高温和高压下弱键断裂、固定电荷重新分布。Semiconductor materials are inevitably contaminated by Na＋ ion while being oxidized.These ions may cause C-V curve of MOS capacitor to shift.Oxidation was performed at 1 200 ℃ in dry O2 to form SiC/SiO2 interface,and MOS capacitor was made,which was processed through different high voltage bias at high temperature and measured with Keithley590 CV analyzer.The density of Na＋ ion in oxide was calculated to be 2.26×1012/cm2.C-V characteristics dose not recover completely after negative bias at high temperature.MOS capacitance in accumulation region decreased after bias-temperature processing,which is different from Si.Reasons for that are poor quality of SiC oxide and interface,weak bonds breaking apart and fixed charges redistributing due to high temperature and high electric field.

关 键 词：6H-SIC Na离子 MOS电容 C-V测试 

分 类 号：TN304.07[电子电信—物理电子学]