The morphological and compositional changes of bimetallic Ti/Al thin film induced by ultra-short laser pulses

B Gaković,A Radulović,S I Kudryashov,P A Danilov,A A Ionin,D Milovanović,P Panjan

doi:10.1140/epjd/s10053-021-00292-4

Abstract

Results regarding morphological and compositional changes of bimetallic thin film (BMTF), composed of aluminium (Al) and titanium (Ti) nano-layers, by single fs laser pulses, are presented. Laser irradiation was conducted in the air with focused, linearly polarized laser pulses, the duration being 300 fs, wavelength 515 nm, and pulse energy up to 1.2~upmu hbox {J}. Effects of the variations of the pulse energy on the changes were studied. In the experiment, single pulse energy values from 0.03 to 0.08 upmu hbox {J} caused ablation–photomechanical spallation of the upper part of BMTF layer from the Si substrate, without ablation of the whole film. Irradiation at higher pulse energies gradually removed the whole BMTF and even a part of the Si substrate. We explained the influence of different electron–phonon dynamics, in the case of multilayered thin films composed of Al and Ti, on BMTF ablation. Damage/ablation threshold, which is minimal pulse energy/fluence sufficient for starting ablation, was calculated.Graphic abstract

Highlights

Thin films are important for many applications, ranges from decoration and protection of materials, through technological usage to environmental and medical purposes
The sample bimetallic thin film (BMTF) that was used in the experiment is composed of two layers, titanium and aluminium
The deposition was performed in a triode sputtering system Sputron (Balzers Oerlikon)

Summary

Introduction

Thin films are important for many applications, ranges from decoration and protection of materials, through technological usage to environmental and medical purposes. Following the steps (3) to (5), irradiation at higher pulse energy/fluence is important for precise laser nanofabrication of metals either in the bulk In the conducted experiment with the single fs laser pulses and BMTF we estimated damage threshold laser fluence and found the “window” of the laser fluences that caused selective ablation/spallation of the first nano-layer and a part of the bottom one.

Results

Conclusion