蒸发速率对ZnS薄膜性能的影响

为了研究蒸发速率对ZnS薄膜的折射率、表面形貌和应力等性能的影响,本文采用电子束蒸发技术进行了ZnS薄膜的制备。首先在K9玻璃基片上镀制薄膜,采用分光光度计进行透射率曲线的测试,利用光谱反演法得出薄膜的折射率,采用原子力显微镜表征了样品的表面形貌。最后在聚酰亚胺基底上镀制薄膜,利用Stoney公式计算出薄膜的应力。结果表明,随着蒸发速率的增加,薄膜折射率先增大后减小,在2000nm波长处薄膜的折射率最大值为2.21,最小值为2.07。蒸发速率越大,薄膜样品表面结构越疏松。不同蒸发速率下制备的薄膜均呈现压应力,增大蒸发速率可以显著降低薄膜应力。ZnS薄膜的性能受蒸发速率影响显著,蒸发速率为1.5nm/s时折射率可达到最大值,蒸发速率为2.5nm/s时薄膜应力最小。

Effect of Evaporation Rate on the Properties of ZnS Films

This work aims to study the effects of evaporation rate on refractive index,surface morphology and stress of ZnS films.Electron beam evaporation was used to prepare the ZnS films.Firstly,the film was deposited on K9 substrate and the transmittance curve was tested by spectrophotometer.The refractive index of the film was obtained by spectral inversion method and the surface morphology of the sample was characterized by atomic force microscope.The film was also deposited on PI substrate and the stress of the film was calculated by Stoney formula.With the increase of evaporation rate,the refractive index first increases and then decreases.At the wavelength of 2000 nm,the maximum refractive index was 2.21,and the minimum was2.07.The higher the evaporation rate,the looser the surface structure of the film sample is.The films prepared at different evaporation rates all show compressive stress.Increasing the evaporation rate can significantly reduce the stress of films.The performance of ZnS film was significantly affected by the evaporation rate.When the rate was 1.5 nm/s,the refractive index can reach the maximum value.When the rate was 2.5 nm/s,the stress can obtain the minimum value.