溅射气压对Ge_2Sb_2Te_5薄膜光学常数的影响

Effects of Sputtering Ar Pressure on the Optical Constants of Ge_2Sb_2Te_5 Thin Films

实验研究了氩气气压对溅射制备的Ge2 Sb2 Te5 薄膜的光学常数随波长变化的影响 ,结果表明 :随薄膜制备时氩气气压的增加 ,Ge2 Sb2 Te5 薄膜的折射率n先增大后减小 ,而消光系数k先减小后增大。二者都随波长的变化而变化 ,且在长波长范围变化较大 ,短波长范围变化较小 ,解释了溅射气压对Ge2 Sb2 Te5

The effects of sputtering Ar pressure on optical constants (n, k) of Ge2 Sb2 Te5 thin films in the wavelength range from 300 nm to 900 nm were studied experimentally. The results show that the refractive index (n) first increases and then decreases with increasing Ar pressure, whereas the extinction coefficient (k) changes with Ar pressure in a contrary way to that of n. The extent of the influence of Ar pressure on n and k also changes with wavelength. It is greater in the long wavelength region than in the short wavelength region. The mechanism on which the optical constants of the Ge2 Sb2 Te5 thin films are affected by the Ar pressure is discussed based on the variation of the atomic density and microstructure of the films.