The Nanosecond Effect of Intense Laser Radiation on Thin TiAlN Films

• Published in: Optics and spectroscopy 2020, Vol.128 (1), p.141-147
• Main Authors: Ivlev, G. D., Zaikov, V. A., Klimovich, I. M., Komarov, F. F., Ludchik, O. R.
• Format: Article
• Language: English
• Subjects: Cellular structure; Cracks; Flux density; Glass substrates; Irradiation; Laser ablation; Lasers; Magnetron sputtering; Nitrides; Optical Devices; Optics; Optics of Surfaces and Interfaces; Photonics; Physics; Physics and Astronomy; Ruby lasers; Silicon films; Silicon substrates; Thermal stress; Thick films; Thin films
• ISSN: 0030-400X; 1562-6911
• DOI: 10.1134/S0030400X20010117

The spectral dependences (λ = 0.35–1.0 μm) of transmittance and reflectance R of binary TiAlN nitride thin films deposited by magnetron sputtering of the target on glass substrates and on Si wafers have been measured. TiAlN/Si films 0.5 μm thick were exposed to single nanosecond (70 ns) pulses of ruby laser radiation in order to study the effect of thermophysical processes laser-induced in TiAlN on the dynamics of R ( t ) at probe wavelengths λ 1 = 0.53 μm and λ 2 = 1.06 μm and on the state of the zones of laser irradiation, which was studied by optical and scanning electron microscopy. The dynamic change of R increase at λ 1 and decrease at λ 2 associated with pulsed heating of the film and which is observed in the experiment increases as irradiation energy density W increases with the approach to the threshold energy of laser ablation of nitride of ~1 J/cm 2 . Laser-induced thermophysical processes occurring at W = 0.6–0.9 J/cm 2 lead to specific modification of the TiAlN layer with the formation of a grid of cracks due to thermal stresses arising during the action of the laser pulse. Increasing W results in a more developed cellular/mesh film structure characterized by a smaller average cell size.