基于电荷补偿的槽栅IGBT设计和工艺研究

Design and Fabrication of Trench Gate IGBT based on Charge Compensation Principle

大功率半导体器件是现代工业和国防进行能量转换及控制的核心器件,也是制约我国电力电子技术水平和竞争力提升的关键器件.本文以降低器件导通电阻和功耗、提高击穿电压为目标研究电荷补偿槽栅IGBT,着重器件结构创新和关键工艺优化.电荷补偿槽栅IGBT导通电阻与器件间隔排列的p、n区半导体层厚及击穿电压成正比,相比传统IGBT导通电阻正比于击穿电压2.5次方理论,同等击穿电压下,允许n区有更高的掺杂浓度,这降低了器件的导通电阻和功耗.采用倾斜角离子注入制作电荷补偿结构,调节注入倾斜角和优化注入剂量是精确控制n区掺杂浓度的有效方法,也是保证器件电参数指标的关键制作工艺.用难熔金属硅化物设计双掩膜版的全自对准制作工艺,系统研究电荷补偿槽栅IGBT工艺制作原理,探索保证器件电参数指标的制作工艺控制机制,提出电荷补偿槽栅IGBT结构和版图设计优化方法和制作工艺参数优化方法.

High power semiconductor devices are the key devices in modern industry and military for energy converter and controlling, they is also the key devices which restrict the development of power electronics and their competition upgrade in our country. The main targets of this paper are decrease the on-resistance and power dissipation and increase its breakdown voltage of the charge compen- sation trench gate IGBT（CCIGBT） by design new device structure combined with control and optimum of the key fabrication processes. A new trench gate power IGBT is proposed in this paper with charge compensation structure in its drift region, which exhibits strongly improved relationship between blocking voltage and on-resistance. The on-resistance of CCIGBT is linearly related with thickness of n drift region and breakdown voltage not the 2.5 power of breakdown voltage relationship for conventional IGBT, so higher doping concen- tration in the n drift region can be used for the same rated breakdown voltage of CCIGBT vs. conventional IGBT and leading the de- crease of the on-resistance for CCIGBT. An accurate control of impurity concentration of n drift region in the trench sidewall is important to achieve the performance of proposed CCIGBT, and angle ion implantation is considered to be the most suitable method for its fine controllability, so we optimized the trench sidewall doping by adjusting the ion implantation dosage and its implanted angles.