Laser Direct Write of Active Thin-Films on Glass for Industrial Flat Panel Display Manufacture

Abstract

New high repetition rate picosecond lasers offer possibility for high efficiency structuring of transparent conductors on glass and other substrates. The results of ablation of the indium-tin oxide (ITO) layer on glass with picosecond lasers at various wavelengths are presented. Laser radiation initiated ablation that formed trenches in ITO. Profile of the trenches was analyzed with a phase contrast optical microscope, a stylus type profiler, SEM and AFM. Clean removal of the ITO layer with the 266 nm radiation was observed when laser fluence was above the threshold of 0.20 J/cm 2 , while for the 355 nm radiation the threshold was higher, above 0.46 J/cm 2 . The glass substrate was damaged in the area where the fluence was higher than 1.55 J/cm 2 . The 532 nm radiation allowed getting well defined trenches, but a lot of residues in the form of dust were generated on the surface. Use of UV laser radiation with fluences close to the ablation threshold made it possible to minimize the recast ridge formation and surface contamination during the process. The latter was confirmed by the scanning Auger spectroscopy. The processing speed of up to 0.5 m/s was achieved when using high repetition rate picosecond lasers in the UV range.

49.3: Mechanism and Advanced Application of Rapid Laser Processing on SnO2 Thin Films for FPD Manufacture

“…By considering the two physical mechanisms, i.e., free carrier collective oscillation and excitation from intermediate levels between conductive and valence bands, we were able to achieve successful processing at low laser energy, i.e., 2 J/cm 2 . This is even lower than the process energy of ITO thin film (2.8 J/cm 2 ) that is currently used in practical PDP manufacturing [5,6]. This result implies that laser processing on SnO 2 thin films can potentially achieve significantly higher speed and low cost in practical manufacturing.…”

“…Laser processing of materials located on the top line partially or completely failed even with 12 J/cm 2 of laser energy. As reference, representative values of ITO and Cr thin film are also shown on the graph [5,6]. Figure 4 shows that materials whose carrier concentration is near λ p could be processed.…”

“…Photolithograny has, however, problems in need of solution such as low productivity and waste chemicals that damage the environment. Therefore, laser processing has been attracting attention as an alternative technique [2,3,5,6]. Most of the previous works consider the processing of Indium Tin Oxide (ITO) thin films because ITO is currently used to make transparent electrode for FPDs.…”

Influence of barrier absorption properties on laser patterning thin organic films

“…The successful patterning of ITO on glass substrates by using Excimer laser 248 nm has been reported by many researchers. Some authors demonstrate the enormous commercial potential of Laser Direct Write (LDW) versus wet-etch lithography for the patterning of ITO on glass for the manufacturing of Plasma Display Panels (PDPs) 6 .…”

Laser direct imaging of transparent indium tin oxide electrodes using high speed stitching techniques

“…[1][2][3][4] In recent years, laser direct imaging (LDI) has been developed to produce the surface texturing, scribing, marking, grooving, depositing, milling, cutting, drilling, and patterning on various materials. Henry et al 5) indicated an optimum industrial fluence of 2.8 J/cm 2 irradiated on ITO thin films with a thickness of 100 nm that could obtain high quality ITO patterns. The process time for a 42'' plasma display panel (PDP) could be less than 20 s fabricated by the laser direct writing technology.…”