斜角蒸镀光学薄膜工艺的研究

Theoretical Analysis and Application Research of Optical Film with Oblique Evaporation

斜角蒸镀方法是制备光学薄膜的常用方法之一。试验证明,采用斜角蒸镀方法沉积薄膜,能改变薄膜晶体结构,从而使薄膜性能得到改变。在蒸发过程中,蒸发材料在基底上形成了倾斜的柱状结构薄膜,而且随着蒸镀过程入射角度的增加,薄膜柱状结构也发生了明显改变,本文结合试验结果对这些影响因素加以分析。通过控制薄膜生长的条件,包括沉积的材料和其它条件,能够将薄膜结构控制精确到10nm级别。在薄膜生长过称中,动量守恒和表面扩散作用是形成这种独特的柱状结构的主要原因。因此,如果能够采用工艺手段改变材料的结构来改变它的折射率,就能使光学薄膜的选材更加广泛,也能扩大光学薄膜应用范围。

Oblique evaporation method of optical film had been applied widely. Different structure of film can be fabricated by oblique evaporation, and the characteristic of film had been changed, for example, refractive index. Ad atom diffusion, conversation of momentum and atomic shadowing are the dominant growth mechanisms with oblique evaporation conditions creating extreme shadowing. In this paper, the relation between vapor incidence direction angle and columnar inclination of deposited film had been shown, and the structure of film had been controlled under lOnm compared with designed structure. The oblique evaporation technique was found to have potentially promising application in optical, chemical device and so on. If we can use technology tools to change the structure of the material to change its refractive index, the optical film materials choice can be increased sharply.