Structural property investigation on obliquely deposited thick Al films

Abstract

As we know, high-quality large-area thick Al films have important applications in echelle gratings. To fabricate them, the deposition angle is one of the most decisive factors. In this study, for the first time we investigate the structural properties of thick Al films deposited by electron beam evaporation at different deposition angles. By measuring film morphology, surface roughness and hardness, we demonstrate the influences of deposition angle on structural properties of thick Al films. A large amount of columnar microstructures and air voids appear in thick Al films with deposition angle increasing, which seriously degrade surface roughness and film hardness. The formation origin of columnar microstructures and air voids is clarified through growth dynamics analysis of Al films. The large deposition angle could significantly reduce the structural properties of Al films. So to attain thick Al films with large-area uniformity and high quality, the deposition angle should be precisely controlled.

Keywords:

• Thick aluminium films
• Deposition angle
• Oblique deposition
• Echelle gratings

Acknowledgements

This research is supported by the National Natural Science Foundation of China (Grant Nos. 61306125 and U1435210), Science and Technology Innovation Project of CIOMP (Grant No. Y3CX1SS143), Science and Technology Innovation Project of Jilin Province (Grant Nos. Y3293UM130 and Y4703UJ140) and Science and Technology Development Project of Jilin Province (Grant No. Y3453UM130).