SiC MOSFET阈值电压漂移评测方法研究

Study on Threshold Voltage Drift Evaluation Method of SiC MOSFET

报道了对SiC MOSFET阈值电压漂移评测方法的研究结果。在器件物理层面上分析了造成器件阈值电压发生漂移的原因,MOS界面陷阱、近界面陷阱、固定电荷以及可移动电荷都会影响阈值电压的漂移。为了衡量器件工艺水平,精准评测器件的阈值电压漂移量,搭建测试平台进行了阈值电压漂移量测试。通过试验发现,阈值电压在应力的作用下既会发生漂移也会恢复,偏置电压去除与阈值电压测试之间的时间间隔非常重要。对阈值电压漂移量的测试应在同样的电压扫描方式、同样的时间间隔以及相同的温度下进行。

The research results of threshold voltage drift evaluation method for SiC MOSFET were reported in this paper.On the physical level of the device,the causes of threshold voltage drift had been analyzed.MOS interface traps,near-interface traps,fixed charges and movable charges all affect the threshold voltage drift.In order to measure the process level of the device and accurately evaluate the threshold voltage drift of the device,a test platform had been built to test the threshold voltage drift.It is found that the threshold voltage will drift and recover under the stress,and the time interval between the removal of bias voltage and the threshold voltage test is very important.The test of threshold voltage drift should be carried out under the same voltage scanning mode,the same time interval and the same temperature.