样品表面覆氧对二次离子发射影响的实验研究

A STUDY ON THE ASPECTS OF OXYGEN ENHANCEMENT IN QUANTITAVE SIMS

本文给出了样品表面充氧对二次离子发射影响的一些新的实验结果。表面氧压变化时,二次离子信号的变化有一暂态过程;二次离子信号饱和时的氧压随元素电负性的增加而增加,当一次离子为0.25mA/Cm^2、充氧压强为7×10^(-6)Torr时,所有元素的二次离子信号均达饱和;电负性大于等于3的元素不发生二次离子产额的氧增强效应。这些现象的研究及SIMS定性和定量分析有着重要意义。

Some new experimental phenomena and resuhs of secondary ion emission on surfaces exposed to oxygen were investigated. The signals of secondary ions donot get to a stable state immediately bnt udergo a temporary process when the oxygen exposure is increasing. The exposed oxygen pressure, at which the intensity of secondary ions tends to saturate, increases with the increasing of the element electronegativity. The intensities of secondary ions for all analyzed elements will become saturated when primary ion intensity is 0.25mA/cm^2 and oxygen pressure is 8×10^(-4)pa. The oxygen enhancements to secondary ion yields have not been observed for the elements whose electronegativities are greater than 3. All of these results are important to the theoretical research of secondary ion emission in qualitative and quantitative SIMS