Conference Program - LOPE-C 2011
Conference Program - LOPE-C 2011
Conference Program - LOPE-C 2011
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SCIENTIFIC CONF. | WEDNESDAY-JUNE 29, <strong>2011</strong><br />
Track 5<br />
Laser Processing (02:30 pm - 04:00 pm) | LOCATION HARMONIE E / LEVEL C2<br />
03:20 pm Laser Ablation of Transparent Conducting Materials for Organic<br />
Mr Moritz Schaefer,<br />
Fraunhofer ILT, Germany<br />
One of the great advantages of polymer electronics is the possibility to produce low cost electronics by fast printing methods. Screen and inkjet printing offer minimal<br />
features sizes of 10 µm and are therefore not accordable with small structure sizes of a few microns or even sub microns as needed for highly integrated circuits. To<br />
achieve structures of this size most of the possible methods are very time consuming and thus cannot be applied in a reel-to-reel process.<br />
Laser processing provides a possible solution for a fast and high resolution patterning method for transparent conducting materials which are needed for OLEDs, organic<br />
photovoltaics, fully transparent displays and transparent circuits. The ablation of such materials as for example ITO (Indium Tin Oxide) and PEDOT/PSS (Poly (3,<br />
4-ethylene dioxythiophene) Poly (styrenesulfonate)) is based on photochemical ablation and stress based evaporation. In this paper the ablation at different wavelengths<br />
from the deep ultraviolet range with excimer lasers up to the infrared range with solid state lasers is discussed. By evaluation of the different thin films using UV/VIS/NIR<br />
spectrometry measurements the optimal wavelength for micro patterning of each material is determined. The different ablation mechanisms at the different wavelengths are<br />
examined.<br />
Special emphasis will be put on the accuracy of the edges of the ablated areas. This has been investigated by different microscopy methods such as optical microscopy,<br />
white light interferometer microscopy (WIM) and atomic force microscopy (AFM). Different patterning methods, like ablation via mask projection, scanner based ablation<br />
and ablation via microscopy optics will be compared concerning process speed and achievable highest resolution.<br />
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