Annealing-Induced Structural and Optical Evolution of Ion-Beam-Sputtered Ta2O5 Films for High-Power Laser Applications
Abstract
Tantalum pentoxide (Ta2O5) thin films deposited by ion beam sputtering (IBS) are essential components in high-power laser systems, where post-deposition annealing is routinely used to optimize film quality. In this work, we systematically investigate the structural and optical evolution of IBS-deposited Ta2O5 single layers subjected to post-deposition annealing at temperatures from 400 to 800 ∘C. The films undergo an amorphous-to-polycrystalline transition between 600 ∘C and 700 ∘C, accompanied by a marked increase in surface roughness. Argon bubbles inherently incorporated during IBS serve as structural markers: their size correlates positively with the surface roughness from the as-deposited to 700 ∘C but decouples at 800 ∘C, revealing a transition from matrix-relaxation-dominated to surface-diffusion-dominated behavior. Transmittance spectra show a red shift at 400 and 600 ∘C which can be explained by physical thickness increase. Weak absorption decreases from ~6 ppm in as-deposited films to ~2 ppm at 400-600 ∘C due to annihilation of oxygen vacancies, rises markedly at 700 ∘C due to grain-boundary defects and then drops again at 800 ∘C as grain boundaries relax. We identify 400 ∘C as the optimal annealing window for IBS-deposited Ta2O5 single layers, with the lowest surface roughness and effectively reducing weak absorption while preserving the amorphous phase.
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BibTeX
@misc{chen2026annealinginduced,
title = {{Annealing-Induced Structural and Optical Evolution of Ion-Beam-Sputtered Ta2O5 Films for High-Power Laser Applications}},
author = {Chang Chen and Yuan Fang and Yanzhi Wang and Jijun Feng and Yesheng Lu and Yu Chen and Ge Zhang and Jianda Shao},
howpublished = {arXiv},
year = {2026},
month = nov,
doi = {10.48550/arxiv.2611.04429},
eprint = {2611.04429},
archivePrefix = {arXiv},
url = {https://arxiv.org/abs/2611.04429},
note = {CC BY 4.0},
}
RIS
TY - UNPB
TI - Annealing-Induced Structural and Optical Evolution of Ion-Beam-Sputtered Ta2O5 Films for High-Power Laser Applications
AU - Chang Chen
AU - Yuan Fang
AU - Yanzhi Wang
AU - Jijun Feng
AU - Yesheng Lu
AU - Yu Chen
AU - Ge Zhang
AU - Jianda Shao
PY - 2026
DA - 2026/11/03
PB - arXiv
DO - 10.48550/arxiv.2611.04429
UR - https://arxiv.org/abs/2611.04429
AB - Tantalum pentoxide (Ta2O5) thin films deposited by ion beam sputtering (IBS) are essential components in high-power laser systems, where post-deposition annealing is routinely used to optimize film quality. In this work, we systematically investigate the structural and optical evolution of IBS-deposited Ta2O5 single layers subjected to post-deposition annealing at temperatures from 400 to 800 ^∘C. The films undergo an amorphous-to-polycrystalline transition between 600 ^∘C and 700 ^∘C, accompanied by a marked increase in surface roughness. Argon bubbles inherently incorporated during IBS serve as structural markers: their size correlates positively with the surface roughness from the as-deposited to 700 ^∘C but decouples at 800 ^∘C, revealing a transition from matrix-relaxation-dominated to surface-diffusion-dominated behavior. Transmittance spectra show a red shift at 400 and 600 ^∘C which can be explained by physical thickness increase. Weak absorption decreases from ~6 ppm in as-deposited films to ~2 ppm at 400-600 ^∘C due to annihilation of oxygen vacancies, rises markedly at 700 ^∘C due to grain-boundary defects and then drops again at 800 ^∘C as grain boundaries relax. We identify 400 ^∘C as the optimal annealing window for IBS-deposited Ta2O5 single layers, with the lowest surface roughness and effectively reducing weak absorption while preserving the amorphous phase.
ER -