Selective laser ablation and patterning on Ag thin films with width and depth control

Abstract

Silver (Ag) films were deposited on glass substrates by radio frequency (RF) magnetron sputtering and then ablated by a 532 nm nanosecond pulsed laser. The effects of laser fluence and defocusing amount on the width and depth of laser-ablated grooves on 100-and 600-nm-thick Ag films were systematically investigated under single-and multi-scan ablation. The results suggested that the Ag films could be successfully removed from the substrate owing to laser-induced thermoelastic force or vaporization. It was confirmed that laser fluence and defocusing amount played very important roles in controlling the width and depth of the laser-ablated grooves. In the present work, grooves with widths ranging from 53 to 196 μm and depths ranging from 56 to 196 nm were obtained on 100-nm-thick Ag films by single-scan laser ablation, and laser ablation or removal with controllable depths was realized on 600-nm-thick Ag films by adopting single-or multi-scan (i.e., scanning numbers of 1-6). Furthermore, square spiral Ag patterns were successfully obtained by single-and multi-scan laser ablation and showed good electrical conductivity in a simple circuit. This work may have great potential applications in various fields that demand width and depth control of laser ablation/removal.

Thermoelastic pulsed laser ablation of silver thin films with organic metal–SiO2 adhesion layer in water: application to the sustainable regeneration of glass microfluidic reactors for silver nanoparticles

“…P A Danilov et al [68,69] recently measured values between 0.1 and 0.4 J cm −2 on films with a thickness of 50 nm, depending on both temporal duration and dimension of the laser pulse. Considering experiments using ns-laser pulse, L Huang et al [49] observed that a clear ablation pattern could still be formed for a working fluence of 0.1 J cm −2 so that F th is lower this value considering their investigation. Our results are consistent with the literature although none of the cited works refer to a possible thermoelastic effect because the working fluences were too high to observe a pure thermoelastic ablation.…”

“…These images give important information about the origin of the PLA process depending on the working fluence. As explained in [43,49], depending on the working fluence, the increase in temperature at the metal/ substrate interface after absorption of the laser pulse may cause different phenomena. As depicted in figure 4, when the temperature is below the fusion point, a thermoelastic force is induced by PLA, which locally enhances the mechanical stress of the thin film.…”

“…Laser writing with fs-laser pulses is based on nonthermal ablation [46] and may be preferred to minimize the heat-affected zone (HAZ) [46,47] and maximize the spatial resolution of the machining process [48]. In the case of ns-laser pulses, the HAZ is limited by working at low fluence (F)<1 J cm −2 [49], and should be as near as possible to its threshold value (F th ). In this case, depending on the value of F and the corresponding temperature gradient in the thin film, it has been observed that ablation of the material may proceed mainly through two routes: i) detachment of thin films because of the thermoelastic force (lower F), and ii) ejection of the material after reaching the melting or evaporation temperature (higher F) [43,49].…”

Thermodynamic effects of pulsed laser multilayer thin film etching

“…However, the research was only performed for simple grooves, and no in-depth study on the processing accuracy and efficiency has been carried out. Jia [6] and Liu [7] adopted a precise removal technology for metal-layer localization based on a numerical control laser to complete the precision processing of typical samples. The three-dimensional metal graphics were precisely joined, with smooth and neat edges.…”

Preparation and Photoelectric Properties of Patterned Ag Nanoparticles on FTO/Glass Substrate by Laser Etching and Driving Layer Strategy

“…Transparent conductive oxide (TCO), as a kind of ceramic material, has been widely applied to photoelectric devices such as flat panel displays [1], solar cells [2,3], organic light emitting devices (OLEDs) [4] and photosensors [5], due to its outstanding optical and electrical properties. Indium tin oxide (ITO), which has been most often used in various optoelectronic applications in the past many years, has now been gradually replaced by other TCO materials because of the scarcity and toxicity of the indium element [6,7].…”