Conference Program - LOPE-C 2011

SCIENTIFIC CONF. | WEDNESDAY-JUNE 29, 2011
Track 5
Laser Processing (02:30 pm - 04:00 pm) | LOCATION HARMONIE E / LEVEL C2
02:30 pm Laser micromachining of organic LEDs
Mr Tino Petsch,
3D-Micromac AG, CEO, Germany
OLED lighting is expected to be one of the fastest growing markets in the area of organic electronics. The state of the art production is mainly based on vacuum deposition
processes, which, in order to simplify the material handling, will most probably be embedded in a roll-to-roll environment. While reducing the handling costs this also implies
challenges to the patterning of the several OLED layers. Laser micromachining applying ultra-short pulsed laser sources has the potential to fully satisfy the requirements.
Within this talk the latest findings on the separate scribing steps P1, P2 and P3 will be presented.
03:00 pm Maskless ultrafast laser trimming of OTFT devices for low leakage fast switching
Dr Michael Cooke,
The Printable Electronics Technology Centre , United Kingdom
Organic thin-film transistor (OTFT) performance has progressed dramatically in recent years approaching fast the commercial realisation of large-area low cost electronic
devices on rigid or flexible substrates. A critical issue in high performance OTFT fabrication is the precise direct patterning of the organic semiconducting layer to leave an
active channel region and the reduction of leakage currents by avoiding conductive paths between devices. This is key for eliminating high resistive and capacitive parasitic
leakage currents at the insulator/semiconductor interface. To date there are few demonstrated manufacturing processes that can achieve the desired effect of improved
on/off ratio without having an adverse effect on the channel mobility. Whilst lithography processes can be used, the addition of further masking steps risks making the
process too lengthy and hence uneconomic at a large scale or in future roll-to-roll processes. This is highly problematic as TFT sizes shrink. Here we discuss an industrial
laser solution for scalable maskless direct trimming of OTFTs for display or other applications using ultrashort DPSS lasers on especially formulated OTFT materials.
Experimental measurements including optical profiling, SEM and electrical device characterisation suggest that clean OSC layer removal results in an improved on/off ratio
with less leakage current whilst producing minimal degredation in mobility. Selective laser patterning could be certainly utilised for athermal, debris-free patterning of
OTFTs with ultraprecise spatial resolution and depth control.
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