3300 V沟槽栅IGBT的衬底材料的优化设计

Optimum Design of Substrate Materials for the 3 300 V Trench Gate IGBT

使用TCAD仿真软件对3 300 V沟槽栅IGBT的静态特性进行了仿真设计。重点研究了衬底材料参数、沟槽结构对器件击穿电压、电场峰值等参数的影响。仿真结果表明,随衬底电阻率增加,击穿电压增加,饱和电压和拐角位置电场峰值无明显变化;随衬底厚度增加,击穿电压增加,饱和电压增加,拐角位置电场峰值降低;随沟槽宽度增加,饱和电压降低,击穿电压和拐角位置电场峰值无明显变化;随沟槽深度增加,饱和电压降低,击穿电压无明显变化,拐角位置电场峰值增加;随沟槽拐角位置半径增加,击穿电压和饱和电压无明显变化,但拐角位置电场峰值减小。选择合适的衬底材料对仿真结果进行实验验证,实验结果与仿真结果相符,制备的IGBT芯片击穿电压为4 128 V,饱和电压约为2.18 V。

The static characteristics of the 3 300 V trench gate IGBT were simulated by using TCAD software. Effects of the parameters of substrate materials and the trench structure on the breakdown voltage and the peak electric field of devices were studied. The simulation results show that with the increase of the substrate resistivity,the breakdown voltage increases,and there are no obvious changes in the saturation voltage and the peak electric field at corner position. With the increase of the thickness of the substrate,the breakdown voltage and the saturation voltage increase,and the peak electric field at corner position decreases. With the increase of the width of the trench,the saturation voltage decreases,and there are no obvious changes in the breakdown voltage and the peak electric field at corner position. With the increase of the depth of the trench,the saturation voltage decreases,there are no obvious changes in the breakdown voltage,and the peak electric field at corner position increases. With the increase of the radius of the trench at corner position,there are no obvious changes in the breakdown voltage and the saturation voltage,and the peak electric field at corner position decreases. The appropriate substrate material is chosen to validate the simulation results. The breakdown voltage of the fabricated trench-IGBT is 4 128 V and the saturation voltage is about 2. 18 V,which are in good agreement with the expected values.