高压大功率器件用高温栅偏测试装置研制

为准确评估硅IGBT和碳化硅MOSFET等高压大功率器件不同电应力及热应力条件下的栅极可靠性，研制了实时测量皮安级栅极漏电流的高温栅偏（high temperature gate bias，HTGB）测试装置。此外，该测试装置具备阈值电压在线监测功能，可以更好地监测被测器件的状态以进行可靠性评估和失效分析。为初步验证测试装置的各项功能和可靠性，运用该测试装置对商用IGBT器件在相同温度应力不同电应力条件下进行分组测试。初步测试结果表明老化初期漏电流逐渐降低，最终漏电流大小与电压应力有良好的正相关性，栅偏电压越大，漏电流越大。该测试装置实现了碳化硅MOSFET器件和硅IGBT器件对高温栅偏的测试需求且适用于各种类型的封装。

High Temperature Gate Bias Test Equipment for High Voltage and High Power Devices

In order to accurately evaluate the gate oxide reliability of silicon IGBTs and silicon carbide MOSFETs under different electrical stresses and thermal stresses, a high temperature gate bias test equipment was developed, which is capable of measuring pico ampere level gate oxide leakage current in real time. Further,an on-line monitoring function of threshold voltage is integrated into the test equipment so as to better monitor the status of the tested equipment for reliability evaluation and failure analysis. With this equipment, the high temperature gate bias of commercial insulated gate bipolar transistor (IGBT) devices were tested under the same temperature stress and different electrical stresses. The leakage current gradually decreases at the initial stage of the test. The leakage current has a decent positive correlation with the voltage level at the end of the test-the larger the gate bias voltage, the larger the leakage current. Suitable for various kinds of packages, this equipment meets the test requirements of for high temperature gate bias of silicon carbide MOSFETs as well as silicon IGBTs.