新生界面陷阱对Fowler-Nordheim电压漂移的影响

Effect of New Generated Interface Traps on Fowler-Nordheim Voltage Shift

用陷阱俘获模型和恒流方法研究了新生界面陷阱对薄氧化层MOS电容器的F-M(Fow-ler-Nordheim)电压(V_(FN))的影响,得到了电压漂移量△V_(FN)随时间变化的解析表述式.分析结果表明:(d△V_(FN))/(dt)vs △V_(FN)曲线可以用几段直线描述.采用线性化技术,可以方便地识别多陷阱现象.并分别提取原生陷阱及新生陷阱参数.实验结果表明:在恒流隧道电子注入的初始阶段,F-N电压漂移量主要由新生界面陷阱的电子俘获过程所决定,紧接着是原生氧化层体陷阱的电子俘获,然后是新生氧化层体陷阱的电子俘获.

Electron trapping model and constant current stress have been used to study the effect ofnew generated interface traps on F-N (Fowler-Nordheim) voltage, V_(FN), in thin SiO_2 MOS ca-pacitors.The constant current-stressed voltage-time (△V_(FN)-t) analytic expressions have beenobtained.It is obvious that d△V_(FN)/dt vs △V_(FN) curve can be separated into three componentswhich are all linear decreasing lines. A linearized technique has been developed to distinguish conveniently multi-trap pheno-menon and extract the trap parameters of the pre-existing traps and that of the new generatedtraps,respectively. The experimental resuhs show that after the constant current tunneling injection of elec-tron into the thin oxide, the initial F-N voltage shift is governed predominantly by the electronrapping of the new generated interface traps, then by the pre-existing bulk oxide traps, andfollowed by that of the new generated oxide traps.