表面电场对3DK9开关晶体管可靠性影响的研究

Study on the Effect of Surface Electric Field on the Reliability of 3DK9 Switch Transistors

针对3DK9开关晶体管在应用中出现表面漏电失效的具体案例进行分析研究。该器件的设计在基极场板边缘处同时出现金属化台阶和表面尖峰电场,这是影响器件可靠性的重要因素。针对原器件结构的缺陷,提出了一种新的器件结构,即采用结终端扩展技术代替基极场板。新结构不仅大大降低了表面尖峰电场,而且避免了金属化台阶与高电场出现在同一区域的情况,从而提高了器件可靠性。

Some failures of 3DK9 switch transistors with higher surface leakage current were analyzed. It was found that both metallization step and surface peak electric field all occured on the base field area, that was an important factor of reducing reliability of devices. To overcome the structural defect, an improved structure using junction termination extension to replace base field was introduced. The new structure can decrease surface peak electric field and avoid the surface peak electric field and the metallization step coming out at the same place. The new structure will increase the reliability of the devices.