薄膜应力对薄膜测量和使用的影响

Influence of Film Stress on Film Measure and Usage

基片在薄膜应力作用下产生宏观弯曲变形,使入射光线的入射角在基片不同位置产生偏差。根据空间两直线夹角公式,计算了入射光线在曲面上任意一点的入射角,得出同一入射方向的光线在曲面不同点具有不同的入射角,即产生入射角度偏差,偏差大小与基片弯曲曲率半径成反比和入射点位置成正比。进而分析了角度偏差对光谱的影响。实验结果表明,离参考点位置越远,波长偏差越大;角度越大,耦合效率越低。实验结果与理论分析一致。

Film stress causes macro-bending deformation of the substrate, and the deformation makes incidence angles of beams vary at different points of the substrate. Based on the formula of spatial line included angle, the incidence angle at various points of the curve surface was computed. It is concluded that the same incidence beams have various incidence angles at various points of the curve surface and the incidence angle deviation is decided by the substrate curvature and the incidence location. Influences of the deviation on spectrum were analyzed, and experimental results show that the further away from reference point, the bigger the wavelength deviation is and are identical with the theory analysis.