Optical properties and microstructure of Ta_2O_5 thin films prepared by oblique angle deposition

• 作 者: 肖秀娣 董国平 贺洪波 齐红基 范正修 邵建达
• 机 构: Shanghai Institute of Optics and Fine Mechanics,Chinese Academy of Sciences,Graduate University of C
• 出 处: Chinese Optics Letters
• 发表日期: 2004年期
• 关键词: oblique evaporation anisotropic packing reaches rotation pillar ultraviolet refr

Tantalum pentoxide thin films are prepared by oblique angle electron beam evaporation.The influence offlux angle on the surface morphology and microstructure is investigated by scanning electron microscopy(SEM).The Ta_2O_5 thin films are anisotropic with highly orientated nanostructure of slanted columns.The porous microstructure of the as-deposited films results in the decrease of effective refractive index andpacking density with increasing deposition angle.The anisotropic structure results in optical birefringence.The in-plane birefringence increases with the increase of deposition angle and reaches the maximum of0.055 at the deposition angle of 70°.Anisotropic microstructure and critical packing density are the twokey factors to influence the in-plane birefringence.

Tantalum pentoxide thin films are prepared by oblique angle electron beam evaporation. The influence offlux angle on the surface morphology and microstructure is investigated by scanning electron microscopy (SEM). The Ta_2O_5 thin films are anisotropic with highly orientated nanostructure of slanted columns. of the as-deposited films results in the decrease of effective refractive index and packing density with increasing deposition angle. The anisotropic structure results in optical birefringence. The in-plane birefringence increases with the increase of deposition angle and reaches the maximum of .055 at the deposition angle of 70 °. Anisotropic microstructure and critical packing density are the two key factors to influence the in-plane birefringence.