退火温度对宽带脉冲压缩光栅载体金属/介质多层高反膜的影响

Effect of Annealing Temperature on Metal/Dielectric Multilayers for Fabricating Broadband Pulse Compression Gratings

分别以金(Au)作为金属层材料,氧化铪(HfO2)与氧化硅(SiO2)作为高低折射率层材料,利用物理气相沉积方法制备了用于宽带脉冲压缩光栅制作的金属/介质多层高反膜,研究了退火温度对其表面均方根粗糙度、反射率及抗化学清洗破坏能力的影响。实验结果表明:退火前后样品表面均方根粗糙度变化很小;提高退火温度能提高金属/介质多层膜的抗化学清洗破坏能力,但反射率会随之下降。250℃退火10 h后金属/介质多层膜不仅可以承受住化学清洗过程,而且反射率下降也比较小,可以作为金属/介质多层膜的最佳退火工艺。

Metal/dielectric multilayers were prepared by physical vapor deposition process using gold as the metal material, HfO2 and SiO2 as high and low refractive index materials, respectively. These stacks were used to fabricate broadband pulse compression gratings. Influences of annealing temperature on the surface root-mean-square roughness, reflectivity and resistance to chemical cleaning damage were investigated. The experimental results indicated that surface root-mean-square roughness of these multilayers changed only slightly after annealing. Their resistance to chemical cleaning damage improved with the annealing temperature increase, whereas their reflectivity decreased. The metal/dielectric multilayers annealed at 250℃ for 10 h could not only endure the process of chemical cleaning, but also slightly decrease the reflectivity, suggesting that it is an optimal annealing process for metal/dielectric multilayers.