内透明集电极IGBT(ITC-IGBT)与PT-IGBT、FS-IGBT的性能比较

Performance Comparison of the Internally Transparent Collector IGBT (ITC-IGBT)、PT-IGBT and FS-IGBT

首次对600V平面型内透明集电极IGBT(ITC-IGBT)、PT-IGBT和FS-IGBT通态电压与关断能耗之间的折中曲线进行了仿真分析和比较。ITC-IGBT是在PT-IGBT结构中的p+型衬底与n型缓冲层之间加入一层厚度很薄、掺杂浓度低于p+衬底的p型内透明集电区,并且在集电区之内、集电结附近设置具有很低过剩载流子寿命的载流子局域寿命控制层,从而实现透明集电极的效果。仿真结果表明,ITC-IGBT具有优良的综合性能,采用缓冲层浓度最优值的ITC-IGBT的折中曲线明显优于PT-IGBT与FS-IGBT。说明ITC-IGBT结构不仅能解决现有透明集电极IGBT超薄片加工工艺难度大的问题,还为进一步改善IGBT器件综合性能提供了新途径。

For the first time device simulation has been performed for 600 V planar Internally Transparent Collector IGBT（ITC-IGBT）, PT-IGBT and FS-IGBT to investigate and compare their trade-off curves of the on-voltage versus the turn-off energy. The structure of the ITC-IGBT is quite similar to that of the PT-IGBT, but a thin layer of localized recombination layer where carriers＇ lifetime is very low is introduced in the collector region near the p-collector/n-buffer junction. The effective collector of the ITC-IGBT is the p-region above the localized recombination layer which is very thin and low-doped. In this way, a transparent collector is realized. It is shown that the ITC-IGBT has a better performance and the trade-off curve of it with an optimized n-buffer concentration can be much better than those of the PT-IGBT and the FS-IGBT. This indicates that while offering a simple fabrication method oriented to replace the highly difficult method of the existing ultra-thin-wafer transparent-collector IGBTs （NPT, FS, etc）, the ITC-IGBT also opens a new way to further improving the over-all performance of the existing IGBTs.