Xu Xingliang, Zhang Lin, Li Lianghui, Li Zhiqiang, Li Juntao, Zhang Jian, Dong Peng
Microsystem and Terahertz Research Center, China Academy of Engineering Physics, Chengdu, China.
Institute of Electronic Engineering, China Academy of Engineering Physics, Mianyang, China.
Discov Nano. 2023 Oct 16;18(1):128. doi: 10.1186/s11671-023-03905-6.
Silicon carbide (SiC) PiN diode has shown substantial promise as the freewheel diode for switch protection in a pulsed system. In this paper, we investigate the carrier lifetime (τ) modulation on pulsed current capability of SiC PiN diodes. The carrier lifetime in 4H-SiC is modulated by the generation of the Z center through neutron irradiation. Surprisingly, we found that the pulsed current of SiC PiN diodes shows a limited improvement when the carrier lifetime (τ) increases from 0.22 to 1.3 μs, while is significantly promoted as the carrier lifetime increases from 0.03 to 0.22 μs. This changing trend is obviously different from the on-state resistance, which decreases with the increased carrier lifetime. The simulation result indicates that the heat generation (i.e., maximum temperature rise) inside the PiN diodes, especially in the drift layer, is remarkably aggravated in the pulse tests for τ < 0.1 μs, but which is significantly suppressed as carrier lifetime rises to 0.2 μs and above. Therefore, the dependence of pulsed current on carrier lifetime is ascribed to the heat generation resulting from the carrier lifetime controlled conductivity modulation effect, which hence affects the temperature rise and brings about the failure of SiC PiN diodes under high pulsed current.
碳化硅（SiC）PIN二极管作为脉冲系统中用于开关保护的续流二极管已展现出巨大潜力。在本文中，我们研究了载流子寿命（τ）对SiC PIN二极管脉冲电流能力的调制。通过中子辐照产生Z中心来调制4H-SiC中的载流子寿命。令人惊讶的是，我们发现当载流子寿命（τ）从0.22 μs增加到1.3 μs时，SiC PIN二极管的脉冲电流改善有限，而当载流子寿命从0.03 μs增加到0.22 μs时，脉冲电流显著提升。这种变化趋势明显不同于通态电阻，通态电阻随载流子寿命增加而降低。模拟结果表明，在τ < 0.1 μs的脉冲测试中，PIN二极管内部，特别是漂移层的发热（即最大温度上升）显著加剧，但当载流子寿命升至0.2 μs及以上时，发热得到显著抑制。因此，脉冲电流对载流子寿命的依赖性归因于载流子寿命控制的电导率调制效应所导致的发热，这进而影响温度上升并导致SiC PIN二极管在高脉冲电流下失效。
