(1. 先进输电技术国家重点实验室(国网智能电网研究院有限公司), 北京 昌平 102209;2. 中国科学院半导体研究所 半导体材料科学重点实验室, 北京 100083)
(1. State Key Laboratory of Advanced Power Transmission Technology, State Grid Smart Grid Research Institute Co., Ltd., Beijing 102209, CHN;2. Key Laboratory of Semiconductor Material Sciences, Institute of Semiconductors, Chinese Academy of Sciences, Beijing 100083, CHN)
阈值电压、栅内阻、栅电容是碳化硅(SiC)金属氧化物半导体场效应晶体管(MOSFET)的重要电学参数,但受限于器件寄生电阻、栅介质界面态等因素,其提取过程较为复杂且容易衍生不准确性。文章通过器件建模和实验测试,揭示了MOSFET的栅电容非线性特征,构建了电容-电阻串联电路测试方法,研究了SiC MOSFET的栅内阻和阈值电压特性。分别获得栅极阻抗和栅源电压、栅极电容和栅源电压的变化规律,得到栅压为-10V时的栅内阻与目标值误差小于0.5Ω,以及串联电容相对栅源电压变化最大时的电压近似为器件阈值电压。相关结果与固定电流法作比较,并分别在SiC平面栅和沟槽栅MOSFET中得到验证。因此,该种电容-电阻法为SiC MOSFET器件所面临的阈值电压漂移、栅极开关振荡现象提供较为便捷的评估和预测手段。
The threshold voltage, gate internal resistance, and the gate capacitance are the key electrical parameters of silicon carbide (SiC) metal-oxide-semiconductor field-effect transistors (MOSFETs). However, the extraction process is complicated and prone to inaccuracies due to the limited factors such as the parasitic resistance, gate-dielectric interface state in the devices. Therefore, through device modeling and experimental testing, the nonlinear characteristics of gate capacitance of MOSFETs were revealed, and a capacitance-resistance series circuit test method was constructed. Then, the gate internal resistance and threshold voltage characteristics of SiC MOSFETs were studied. The variation law of gate impedance and gate-source voltage, gate capacitance and gate-source voltage were obtained separately in this paper, revealing that when at a gate voltage of -10V, the error between the gate internal resistance and the target value was less than 0.5Ω. Meanwhile, the voltage at the maximum variation of series capacitance with respect to the gate source voltage was approximated as the device threshold voltage. The results were compared with those attained by the constant current method, and verified in SiC planar-gate and trench-gate MOSFETs respectively. Therefore, this capacitance-resistance method provides a relatively convenient method for evaluating and predicting the characteristics of the threshold voltage drift and gate switching oscillations in SiC MOSFET.
杨霏,田丽欣,申占伟,张文婷,孙国胜,魏晓光.碳化硅MOSFET电学参数的电容-电阻法评估[J].半导体光电,2022,43(4):770-776. YANG Fei, TIAN Lixin, SHEN Zhanwei, ZHANG Wenting, SUN Guosheng, WEI Xiaoguang. Evaluation of the Electrical Parameters of SiC MOSFET by Capacitance-Resistance Method[J].,2022,43(4):770-776.复制