郭登耀, 汤晓燕, 李林青, 张玉明. 4 H-SiC PiN功率二极管dV/dt可靠性机理研究[J]. 中国电力, 2021, 54(12): 86-93. DOI: 10.11930/j.issn.1004-9649.202107043
引用本文: 郭登耀, 汤晓燕, 李林青, 张玉明. 4 H-SiC PiN功率二极管dV/dt可靠性机理研究[J]. 中国电力, 2021, 54(12): 86-93. DOI: 10.11930/j.issn.1004-9649.202107043
GUO Dengyao, TANG Xiaoyan, LI Linqing, ZHANG Yuming. Research on dV/dt Reliability Mechanism of 4 H-SiC PiN Power Diode[J]. Electric Power, 2021, 54(12): 86-93. DOI: 10.11930/j.issn.1004-9649.202107043
Citation: GUO Dengyao, TANG Xiaoyan, LI Linqing, ZHANG Yuming. Research on dV/dt Reliability Mechanism of 4 H-SiC PiN Power Diode[J]. Electric Power, 2021, 54(12): 86-93. DOI: 10.11930/j.issn.1004-9649.202107043

4 H-SiC PiN功率二极管dV/dt可靠性机理研究

Research on dV/dt Reliability Mechanism of 4 H-SiC PiN Power Diode

  • 摘要: 碳化硅(SiC)功率开关高速和高功率的特点,使其在脉冲功率系统中面临着比硅(Si)器件更严苛的高dV/dt可靠性问题。实验发现高dV/dt应力会导致4H-SiC PiN功率二极管击穿特性永久退化。仿真结果表明:高dV/dt应力下器件终端区与主结交界处存在较强电场集中,致使雪崩提前发生,进而导致局部温度升高造成永久损伤。该电场集中是由于高dV/dt应力下(JTE)区耗尽不充分所致,提出对JTE区进行高浓度补偿掺杂来提高铝(Al)原子的电离率,进而改善脉冲应力下JTE耗尽不充分问题。仿真证明该方法可以有效降低脉冲应力下主结边缘处的电场集中,6×1020 cm–3的磷(P)原子补偿掺杂使得器件的抗dV/dt能力提升约30%,而静态特性不受影响。该研究为提升JTE终端SiC功率器件dV/dt可靠性提供了思路。

     

    Abstract: Silicon carbide (SiC) power switches have the advantages of high-speed and high-power, which leads to more severe high dV/dt reliability issues than silicon (Si) devices in pulsed power systems. It has been verified by experiments that high dV/dt stress will cause permanent degradation of the breakdown characteristics of 4H-SiC PiN power diodes. Simulation results show that there is a strong electric field concentration at the junction between the terminal area of the device and the main junction under high dV/dt stress, which causes the avalanche to occur early, and in turn leads to local temperature rise and permanent damage. The electric field concentration is caused by insufficient depletion of the junction terminal extension (JTE) region under high dV/dt stress. This paper proposes high-concentration compensation doping to the JTE region so as to increase the ionization rate of aluminum (Al) atoms, thereby improving the insufficient depletion of JTE under pulse stress. Simulation proves that this method can effectively reduce the electric field concentration at the edge of the main junction under pulse stress. The 6×1020 cm–3 phosphorus (P) atom compensation doping improves the device's anti dV/dt capability by about 30%, while the static characteristics are not affected. The proposed method could be a viable way to improve the dV/dt reliability of JTE terminal SiC power devices.

     

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