Direct-write patterning of indium-tin-oxide film by high pulse repetition frequency femtosecond laser ablation

Abstract

Ablation of indium oxide doped with tin oxide (ITO) from glass substrates is described. Laser pulse energy and focus spot size were varied in single-pulse, single-spot ablation tests and for ablation of linear features with scanned multiple pulses. The single-pulse ablation threshold of ITO was smaller than that of the glass substrate so the entire thickness of ITO could be removed in a single pulse or with overlying multiple pulses without the possibility of substrate ablation. Linear features could be created at much higher scanning speeds using a high repetition frequency (100 kHz) Yb fiber amplified laser as compared to a lower repetition frequency (2 kHz) laser. An analysis showed that incubation effects lowered ITO ablation thresholds when pulse frequency was high relative to scanning speed, contributing to large feasible scanning speeds for high pulse frequency lasers.

Continuous modulations of femtosecond laser-induced periodic surface structures and scanned line-widths on silicon by polarization changes

“…However, high precision formation of LIPSS remains a big challenge, which limits industry applications. Compared to other physical and chemical methods for preparations of large-area, uniform nanoscale structures [16], direct laserscanning-induced LIPSS on a material's surface using femtosecond (fs) pulses is quite simple and efficient, which open new possibilities for nanofabrication [11,[17][18][19]. As a key parameter, the scanning interval is of great importance in the formation of large-area, uniform LIPSS, which significantly affects the continuity of the LIPSS and the processing efficiency.…”

Ultrashort Laser Pulses Machining

“…One of those is the probabilistic defect accumulation model [62] that, although widely used for different material classes [65][66][67], does not predict the ablation threshold saturation; other is the exponential defect accumulation model, in which the lowering of the ablation threshold increases the defect creation probability for the next pulse, until the defects saturation is reached and a constant value of Fth for the superposition of many pulses is established [59,60,63]. In this exponential model, the ablation threshold for the superposition of N pulses, Fth,N, can be described by [63]: …”

Why Pulse Duration Matters in Photovoltaics

“…liu [1] and later adopted for thin film-removal by several other researchers. [2,3,4] the method involves generating single-pulse laser damage features at different pulse energies (but the same focus spot size), measuring the diameters of the features, and using log-linear regression techniques to infer the relevant threshold fluence. this technique is attractive because in addition to the threshold information, it also allows for precise experimental determination of the optical spot size that was used to generate the features.…”