退火对电子束热蒸发Al2O3薄膜性能影响的实验研究

用电子束热蒸发方法镀制了Al2O3材料的单层膜，对它们在空气中进行了250～400℃的高温退火。对样品的透射率光谱曲线进行了测量，计算了样品的消光系数、折射率和截止波长。通过X射线衍射仪(XRD)测量分析了薄膜的微观结构，采用表面轮廓仪测量了样品的表面均方根粗糙度。结果发现随着退火温度的提高光学损耗下降，薄膜结构在退火温度为400℃时仍然为无定形态，样品的表面粗糙度随退火温度的升高而增加。引起光学损耗下降起主导作用的是吸收而不是散射，吸收损耗的下降主要是由于退火使材料吸收空气中的氧而进一步氧化，从而使薄膜

The effects of annealing on electron-beam evaporated single Al₂O₃ layers were investigated. The films were annealed in air for 1.5 hours at different temperatures from 250～400 ℃. The transmittance spectra were measured in the wavelength range of 190~400 nm. Microstructures of the samples were characterized by X-ray diffraction (XRD). Profile and surface roughness measurement instrument was used to determine the rms surface roughness. It was found that the transmission spectra shifted to short wavelength gradually as the annealing temperature increased and the total optical loss decreased. The film structure remained amorphous even after annealing at 400 ℃ temperature. And the samples annealed at higher temperature had the higher rms surface roughness. The decreasing optical loss with annealing temperature was attributed to the reduction of absorption owing to oxidation of the film by annealing.