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60Co伽马射线总电离剂量辐照下SiC MOSFET的退化机理分析与建模
Degradation Mechanism Analysis and Modeling of SiC MOSFETs Under 60Co Gamma Ray Total Ionizing Dose Irradiation
| 作者 | Runding Luo · Yuhan Duan · Tao Luo · Yifei Chang · Wenhua Shi · Xiaoyan Xu |
| 期刊 | IEEE Transactions on Electron Devices |
| 出版日期 | 2025年5月 |
| 技术分类 | 功率器件技术 |
| 技术标签 | SiC器件 |
| 相关度评分 | ★★★★ 4.0 / 5.0 |
| 关键词 | 碳化硅MOSFET 总电离剂量 阈值电压漂移 辐照退化 预测模型 |
语言:
中文摘要
研究了碳化硅（SiC）垂直双扩散金属氧化物半导体场效应晶体管（VDMOSFET）和沟槽金属氧化物半导体场效应晶体管（MOSFET）在 $^{60}$Co $\gamma$ 射线辐照环境下的退化机制。探究了不同总电离剂量（TID）辐照后，处于不同工作状态的 SiC MOSFET 电学特性的退化情况。通过辐照后的退火实验研究了辐照过程中产生的缺陷。揭示了 TID 导致 SiC MOSFET 退化的原因，并提出了阈值电压（$V_{\text {th}}$）漂移的预测模型，且通过 TCAD 仿真进行了验证。在不同辐照剂量和退火条件下测量了阈值电压（$V_{\text {th}}$）、击穿电压（BV）、导通电阻（$R_{\text {on}}$）、输入电容（$C_{\textit {iss}}$）、输出电容（$C_{\textit {oss}}$）和反向传输电容（$C_{\text {rss}}$）。实验结果表明，导通电阻（$R_{\text {on}}$）和输入电容（$C_{\textit {iss}}$）的退化主要是由阈值电压（$V_{\text {th}}$）漂移引起的。随着剂量增加，阈值电压（$V_{\text {th}}$）的漂移逐渐达到饱和。沟槽 MOSFET 呈现出与 VDMOSFET 相似的趋势，但对 TID 更为敏感。此外，与高栅极偏置条件下的 MOSFET 相比，零电压偏置的 MOSFET 阈值电压（$V_{\text {th}}$）漂移更小。此外，还计算了辐照和退火过程中栅氧化层中缺陷的增加情况。最后，建立了预测阈值电压（$V_{\text {th}}$）漂移路径的模型，并确定了其准确性和局限性。本研究为 TID 对 SiC MOSFET 的影响提供了有价值的见解。
English Abstract
The degradation mechanisms of silicon carbide (SiC) VDMOSFET and trench metal oxide semiconductor field effect transistor (MOSFET) in a 60Co gamma irradiation environment were investigated. The degradation of electrical characteristics of SiC MOSFET in different working states after irradiation with different total ionizing doses (TIDs) was explored. The defects induced during the irradiation process were studied in annealing experiments conducted after irradiation. The reasons for the degradation of SiC MOSFET caused by TID were revealed, and a prediction model of threshold voltage ( V_ th ) shift was proposed and verified through TCAD simulation. The V_ th , breakdown voltage (BV), on-resistance ( R_ on ) , input capacitance ( C_ iss ) , output capacitance ( C_ oss ) , and reverse transfer capacitance ( C_ rss ) were measured at different irradiation doses and annealing conditions. Experimental results indicated that the degradation of both R_ on and C_ iss was primarily caused by the V_ th shift. As the doses increased, the shift in V_ th gradually reached saturation. Similar trends to VDMOSFET were observed in trench MOSFET but with greater sensitivity to TID. In addition, MOSFETs biased at zero voltage exhibited lower shifts in V_ th compared with those under high gate bias conditions. Furthermore, the increase in defects in the gate oxide during irradiation and annealing processes were calculated. Finally, a model predicting V_ th shift path was established, and its accuracy and limitations were determined. This study provides valuable insights into the effect of TID on SiC MOSFETs.
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SunView 深度解读
从阳光电源的业务视角来看，这项关于SiC MOSFET在总电离剂量辐射环境下的退化机理研究具有重要的战略参考价值。SiC功率器件已成为我司光伏逆变器、储能变流器等核心产品的关键元件，其可靠性直接影响系统的长期性能表现。
该研究揭示了γ射线辐射导致SiC MOSFET阈值电压漂移、导通电阻增大等退化现象，这对我司产品在特殊应用场景具有指导意义。虽然常规地面光伏和储能系统辐射剂量有限，但该研究的价值在于：第一，为极端环境应用（如高海拔、航天级储能系统）提供器件选型依据；第二，研究建立的阈值电压漂移预测模型和TCAD仿真方法，可迁移应用于其他长期应力条件下的可靠性评估，如高温、高湿等实际工况。
论文发现沟槽型MOSFET对辐射更敏感，且零偏压状态下退化较轻，这为我司功率模块的工作模式优化提供了思路。通过合理的栅极偏压管理策略，可能延长器件寿命。此外，退化饱和特性的发现表明器件具有一定的抗辐射裕量，有助于建立更精确的寿命预测模型。
技术挑战在于如何将实验室辐射加速老化数据转化为实际应用场景的可靠性指标。建议我司技术团队关注该类研究方法论，建立自有的SiC器件多应力耦合退化数据库，结合大数据分析提升逆变器和储能系统的预测性维护能力，这将成为产品差异化竞争的重要技术壁垒。