Design and Characterization of High-Voltage 4H-SiC p-IGBTs
Design and Characterization of High-Voltage 4H-SiC p-IGBTs
复制标题
高压 4H-SiC p-IGBT 的设计和表征
DOI：
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发表时间：
2008
影响因子：
3.1
通讯作者：
A. Huang
中科院分区：
文献类型：
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作者：
Qingchun Zhang;Jun Wang;C. Jonas;R. Callanan;J. Sumakeris;S. Ryu;M. Das;A. Agarwal;J. Palmour;A. Huang
高压 p 沟道 4H-SiC 绝缘栅双极晶体管 (IGBT) 已经制造出来并进行了表征。该器件在 100 A/cm2 时的正向压降为 7.2 V，在 25℃ 时具有 -16 V 栅极偏压，对应于 72 mΩ ldr cm2 的特定导通电阻和 26 mmOmega ldr cm2 的差分导通电阻。通过优化 n+ 阱掺杂分布和栅极氧化工艺，在阈值电压为 -6 V 的反型沟道中实现了 12 cm2/V ldr s 的空穴迁移率。采用新型电流增强层来降低 JFET 电阻，并通过改善空穴电流扩散和抑制通过顶部 n-p-n 晶体管的电子电流传导来增强电导率调制。电感开关结果表明，p-IGBT 在 25℃、4kV 直流母线电压和 6A 负载电流下具有约 1μs 的关断时间和 12mJ 的关断能量损耗。测得的感性负载开关波形和数值模拟的关断轨迹表明，p-IGBT 具有接近平方的反向偏压安全工作区域。通过研究漂移层寿命和 p 缓冲层参数的影响，进行了数值模拟，以实现正向电压降和关断能量之间的改进权衡。 SiC p-IGBT 的优点，例如极低的导通电阻、轻微的正温度系数、高开关速度、小开关损耗和大的安全工作区域等潜力，使其适用于大功率高频应用并具有吸引力。
High-voltage p-channel 4H-SiC insulated gate bipolar transistors (IGBTs) have been fabricated and characterized. The devices have a forward voltage drop of 7.2 V at 100 A/cm2 and a -16 V gate bias at 25degC, corresponding to a specific on-resistance of 72 mOmega ldr cm2 and a differential on-resistance of 26 mmOmega ldr cm2. Hole mobility of 12 cm2/V ldr s in the inversion channel with a threshold voltage of -6 V was achieved by optimizing the n+ well doping profile and gate oxidation process. A novel current enhancement layer was adopted to reduce the JFET resistance and enhance conductivity modulation by improving hole current spreading and suppressing the electron current conduction through the top n-p-n transistor. Inductive switching results have shown that the p-IGBT exhibited a turn-off time of ~1 mus and a turn-off energy loss of 12 m J at 4-kV dc-link voltage and 6-A load current at 25degC. The turn-off trajectory from the measured inductive load switching waveforms and numerical simulations shows that the p-IGBT had a near-square reverse bias safe operating area. Numerical simulations have been conducted to achieve an improved tradeoff between forward voltage drop and switching off energy by investigating the effects of drift layer lifetime and p-buffer layer parameters. The advantages of SiC p-IGBTs, such as the potential of very low ON-state resistance, slightly positive temperature coefficient, high switching speed, small switching losses, and large safe operating area, make them suitable and attractive for high-power high-frequency applications.