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    苏艳

    • 教授     博士生导师   硕士生导师
    • 性别:女
    • 毕业院校:大连化物所
    • 学位:博士
    • 所在单位:物理学院
    • 学科:凝聚态物理
    • 办公地点:科技园大厦C座309
    • 电子邮箱:su.yan@dlut.edu.cn

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    Synergistic passivation effects of nitrogen plasma and oxygen plasma on improving the interface quality and bias temperature instability of 4H-SiC MOS capacitors

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    论文类型:期刊论文

    发表时间:2020-05-30

    发表刊物:APPLIED SURFACE SCIENCE

    收录刊物:EI、SCIE

    卷号:513

    ISSN号:0169-4332

    关键字:4H-SiC; MOS capacitor; Density of interface traps; Bias temperature instability; Synergistic effects; Post-oxidation annealing

    摘要:Interface properties and bias temperature instability (BTI) determine the performance and stability of SiC metaloxide semiconductor (MOS) devices. In this work, we propose an electron cyclotron resonance microwave nitrogen-oxygen (N-O) mixed plasma post-oxidation annealing (POA) process to improve the interface properties and BTI of 4H-SiC MOS capacitors. Results showed that the N-O mixed plasma POA reduces the density of interface traps, maintains the stability of the flat band voltage (V-fb) hysteresis under four successive cycles of positive bias temperature stress (PBTS) and negative bias temperature stress (NBTS) at 423 K, and significantly reduces the V(fb )hysteresis under alternating PBTS and NBTS at 100 K. The oxide traps remarkably decreased to 2.27 x 10(12) cm(-2) after N-O mixed plasma POA. The related passivation and improvement mechanisms were further studied by secondary ion mass spectroscopy, X-ray photoelectron spectroscopy, and density functional theory calculations. The synergistic effects of highly reactive N and O plasma promoted the considerable absorption of N at the interface and prevented further oxidation of the SiC substrate. We also elaborate on the effects of N, O, and N-O plasma on the elimination and passivation of O vacancy defects, C-related defects (SiOxCy and C dimer), and Si interstitial defects and discuss implications of the simultaneous suppression of electron and hole trapping.