溅射气压对Si／Ge多层膜结构光学常数的影响

采用可变入射角全自动椭圆偏振光谱仪，测量了用磁控溅射法制备的Si/Ge异质多层膜结构的光学常数，测量能量范围为1．5－4．5eV，分析了不同氩气压强对磁控溅射制备的Si/Ge异质多层膜结构的光学常数的影响，实验结果表明，在低能区域，随压强的增加，多层膜结构的所有光学常数均有不同程度的增加，但在高能区域，溅射气压对光学常数的影响不再明显，多层膜结构的复介电常数的实部和虚部及折射率n的峰位随压强增大而向低能方向位移，多层膜结构的消光系数k的峰位随压强的变化很小，但其峰值随压强的增加而增加。

EFFECTS SPUTTERING Ar PRESSURE ON THE OPTICAL CONSTANTS OF Si/Ge MULTILAYERS

The optical constants of Si/Ge multilayers, which prepared by magnetron sputtering system, have been measured by spectroscopic ellipsometry. The measured photo energy range is from 1.5eV to 4.5eV. The effects of sputtering Ar pressure on optical sonstants of Si/Ge multilayers have been analyzed. The results show that the optical constants of Si/Ge multilayers increase with Ar pressure increasing in different degree within lower energy range, but the effects of Ar pressure are no more obvious in higher energy range. The peak positions of the complex dielectric functions and refractive index shift to lower energy direction with Ar pressure increasing. However, the changes of the peak positions of the extinction coefficient are very small, and their values increase with Ar pressure increasing.