Impact of STI indium implantation on reliability of gate oxide

The impacts of shallow trench isolation(STI)indium implantation on gate oxide and device characteristics are studied in this work.The stress modulation effect is confirmed in this research work.An enhanced gate oxide oxidation rate is observed due to the enhanced tensile stress,and the thickness gap is around 5%.Wafers with and without STI indium implantation are manufactured using the 150-nm silicon on insulator(SOI)process.The ramped voltage stress and time to breakdown capability of the gate oxide are researched.No early failure is observed for both wafers the first time the voltage is ramped up.However,a time dependent dielectric breakdown(TDDB)test shows more obvious evidence that the gate oxide quality is weakened by the STI indium implantation.Meanwhile,the device characteristics are compared,and the difference between two devices is consistent with the equivalent oxide thickness(EOT)gap.     

ZrF分子基态(X~2Δ)的光谱研究

现有Zr F分子的理论值与实验值偏差较大,且有一些光谱参数暂时还没有实验结果.本文基于群论及原子分子反应静力学推导出了Zr F分子的基态电子状态(X2Δ)和合理的离解极限.采用密度泛函理论(B3LYP,B3P86)和二阶微扰理论(MP2)方法,对Zr和F原子分别选择不同的基组进行结构优化和频率计算,根据计算结果及现有实验数据,分析得出在MP2方法下,对Zr使用Lan L2DZ基组,对F使用AUG-cc-PVTZ基组计算得出的结构与实验值较为符合.然后根据优化后的方法及基组扫描了基态Zr F分子的单点能,得到的基态Zr F分子的势能曲线数值,通过Level 8.0软件拟合了势能曲线并得出了一些光谱常数.最后,由拟合得到的光谱常数(De,ωe,ωeχe,Te,Be)与实验值和其他理论值进行了比较.本文的计算结果(Re=0.1859nm,De=7.1046e V,ωe=701.25cm-1,ωeχe=2.6398cm-1,Te=-9.3473cm-1,Be=0.3104cm-1)更接近于实验值.