Abstract
We investigate selective patterning of ultra-thin 20 nm Indium Tin Oxide (ITO) thin films on glass substrates, using 343, 515, and 1030 nm femtosecond (fs), and 1030 nm picoseconds (ps) laser pulses. An ablative removal mechanism is observed for all wavelengths at both femtosecond and picoseconds time-scales. The absorbed threshold fluence values were determined to be 12.5 mJ cm-2 at 343 nm, 9.68 mJ cm-2 at 515 nm, and 7.50 mJ cm-2 at 1030 nm for femtosecond and 9.14 mJ cm-2 at 1030 nm for picosecond laser exposure. Surface analysis of ablated craters using atomic force microscopy confirms that the selective removal of the film from the glass substrate is dependent on the applied fluence. Film removal is shown to be primarily through ultrafast lattice deformation generated by an electron blast force. The laser absorption and heating process was simulated using a two temperature model (TTM). The predicted surface temperatures confirm that film removal below 1 J cm-2 to be predominately by a non-thermal mechanism.
| Original language | English |
|---|---|
| Pages (from-to) | 70-78 |
| Number of pages | 9 |
| Journal | Optics and Lasers in Engineering |
| Volume | 81 |
| Early online date | 9 Feb 2016 |
| DOIs | |
| Publication status | Published - Jun 2016 |
| Externally published | Yes |
Funder
This work is supported under an IRCHSS research Grant no. PS/2010/2331 . This work was conducted under the framework of the INSPIRE programme, funded by the Irish Government׳s Programme for Research in Third Level Institutions, Cycle 4, National Development Plan 2007–2013. Marie Curie Industry-Academia Partnership and Pathways (IAPP) project, Laser-Connect, funded under FP7-People-IAPP-2009-251542 and SFI Industry Research Fellowship 14/IF/2539.Keywords
- ITO
- Thin films
- Laser
- Ablation
- Femtosecond
ASJC Scopus subject areas
- Electronic, Optical and Magnetic Materials
- Atomic and Molecular Physics, and Optics
- Mechanical Engineering
- Electrical and Electronic Engineering