沟道宽长比对深亚微米NMOSFET总剂量辐射与热载流子损伤的影响

本文对不同沟道宽长比的NMOSFET进行了辐射与热载流子应力的试验研究,电参数测量数据表明: 虽然两种损伤的原理具有相似之处,但总剂量辐射与热载流子的损伤表现形式及对沟道宽长比的依赖关系均不同.辐射损伤的最大特点是关态泄漏电流增加,并且损伤与沟道宽长比成反比;热载流子损伤会造成跨导等参数的显著变化,但关态泄漏电流无明显改变,并且损伤随沟道长度与宽度的减小而增大.从二者基本原理出发,结合宏观参数的表现形式,文中对辐射与热载流子损伤进行了详细分析,认为造成二者损伤差异及对沟道宽长比不同依赖关系的原因在于辐射与热载子注入引入的陷阱电荷部位不同.因此对两种损伤进行加固时应重点从器件设计尺寸、结构等方面综合考虑.

The influence of channel size on total dose irradiation and hot-carrier effects of sub-micro NMOSFET

Total dose irradiation and the hot-carrier damages are two of the important factors for the application of sub-micro and even smaller MOS devices. Therefore, how to prevent the device from being damaged attracts much attention. Total dose irradiation and hot-carrier effects of sub-micro NMOSFET with various channel sizes are studied. Electronic parameters are measured and the results show that though the principles of damages are somewhat similar, the total dose irradiation and the damage behavior and their dependences on the width-to-length(W/L) ratio of channel size for these two effects are different. The most notable damage of radiation lies in the great increase of the off-state leakage current, and the damage increases with W/L reducing. While for hot-carrier effect, several parameters such as trans-conductance change a lot, except for the off-state leakage current. And the damage increases as channel length and channel width decrease. The different damage behaviors and different relations to channel size are attributed to the different location of charges induced. Therefore, different aspects should be considered when the device is hardened against these two effects.