Excimer laser beam/ITO interaction: from laser processing to surface reaction

Abstract

We investigated interactions between UV light and Indium Tin Oxide (ITO) thin films sputtered at room temperature. Owing to their photon energy, higher than the band gap of In2O3 (3.5–4.0 eV), KrF (5.0 eV) or XeCl (4.0 eV) lasers proved useful, at high fluences (1‐3 J/cm2) for minute laser shaping, at low fluences (100 mJ/cm2) for laser annealing, or even at very low fluences for gases desorption. Sputtered ITO becomes totally amorphous when an oxygen flow is mixed in the process argon and adjusted for the lowest resistivity. As non optimised layers behave like gas sensors, amorphous ITO is immune to atmospheric agents. The band structure of indium oxide and exposures to UV light at selected wavelengths helped to a better understanding of the gas sensing mechanisms on oxygen rich and oxygen poor layers. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)

Optical and electrical properties of SnO2thin films after ultra-short pulsed laser annealing

“…[2]. Strong interest for TCO materials led recent research to investigate the effects of post-deposition annealing by nanosecond (ns) pulsed lasers on the optical and electrical properties of different TCOs [3][4][5][6][7][8][9][10]. The use of rapid thermal laser annealing, as an alternative process to conventional furnace annealing, is a cost effective solution.…”

Loss Reduction Technique in Ferroelectric Tunable Devices by Laser Microetching. Application to a CPW Stub Resonator in <inline-formula> <tex-math notation="LaTeX">$X$ </tex-math> </inline-formula>-Band

“…This technique is one of the available processes to remove material from a solid surface [32]. It has been preferred to standard wet-etching process since this is a maskless technology that allows getting fast prototyping results.…”

Femtosecond laser processing of indium-tin-oxide thin films

“…Since an a-ITO thin film has a more rapid etching rate than a c-ITO structure [13], some researchers utilized the long pulsed laser annealing process followed by wet etching to fabricate a c-ITO pattern from a-ITO thin films [3,[14][15][16]. In our previous studies, a process to fabricate a crackless c-ITO pattern by the high repetition rate (80 MHz) femtosecond laser-induced crystallization process with a heat accumulation effect was reported [17].…”

“…Since the crystalline structure usually has more physical properties than an amorphous structure does, the as-deposited amorphous-ITO (a-ITO) thin film usually undergoes furnace annealing at a temperature higher than 200 1C [1] and changes to crystalline-ITO (c-ITO) film. To achieve local and rapid thermal heating, a laser annealing process with a nanosecond pulsed laser [2,3] or ultra-short pulsed laser [4] of ITO is presented. The annealed c-ITO film is then usually patterned by a photolithography process, which is a complicated and time-consuming process, e.g.…”