1.2 kV氧化槽交替隔离型RC-IGBT的结构设计及特性研究

提出了一种1.2kV氧化槽交替隔离型RC-IGBT结构。通过采用和正面栅极工艺相同的沟槽刻蚀技术,在器件背面形成交替出现的氧化槽,氧化槽结构增大了RC-IGBT背部N^+ Collector和P^+ Collector之间的短路电阻,从而从根本上消除了传统结构的电压折回(Snapback)现象。为了不增加工艺难度,氧化槽的宽度和栅极的宽度完全一致。研究了氧化槽的深宽比对Snapback现象的影响规律,以及氧化槽之间N^+ Collector与P^+ Collector掺杂长度对器件特性的影响。结果表明,新结构的设计能完全消除Snapback现象,且相较传统结构,元胞尺寸减小了一半,并且器件恢复损耗降低了30%。

Structure Design and Characteristics Research on 1.2 kV RC-IGBT with Alternating Isolated Oxide Trench

A novel 1.2 kV RC-IGBT structure with isolated alternating oxide trench was presented. By using the same trench etching technique as the front gate process, an alternate oxidation trench was formed on the back side of the device, and the oxidation trench structure increased the short-circuit resistance between the N^+ Collector and the P^+ Collector on the back of the RC-IGBT. The Snapback phenomenon of the traditional structure was completely eliminated. The width of the oxidation trench and the width of the gate was exactly the same without increasing the difficulty of the process. The effect of the aspect ratio of the oxidation trench on the Snapback phenomenon and the effect of the N^+ Collector and P^+ Collector doping lengths on the device characteristics between the oxidation trenches were investigated. The results show that the design of the new structure can completely eliminate the Snapback phenomenon, and compared with the traditional structure, the cell size is reduced by half, and the device recovery loss is reduced by 30%.