| AVS 64th International Symposium & Exhibition | |
| Thin Films Division | Thursday Sessions |
| Session TF-ThP |
| Session: | Thin Films Poster Session |
| Presenter: | Premysl Fitl, University of Chemistry and Technology Prague, Czech Republic |
| Authors: | P. Fitl, University of Chemistry and Technology Prague, Czech Republic J. Vlcek, University of Chemistry and Technology Prague, Czech Republic D. Tomecek, University of Chemistry and Technology Prague, Czech Republic E. Maresova, University of Chemistry and Technology Prague, Czech Republic S. Havlova, University of Chemistry and Technology Prague, Czech Republic M. Novotny, Institute of Physics ASCR, Czech Republic J. Lancok, Institute of Physics ASCR, Czech Republic M. Vrnata, University of Chemistry and Technology Prague, Czech Republic |
| Correspondent: | Click to Email |
Focused Laser beam is a widely used for deposition, localized annealing and patterning of various materials (eg. Metals, oxides, organic substances). Our work is focused to possibilities of usage of continuous wave (CW) lasers for local deposition and patterning of inorganic and organic semiconductors.
The source substrates were prepared as follows: Thin glass slides with sputtered metal layer (gold - thickness ~ 100 nm) were cleaned and dried. Side with sputtered metal was then covered with a thin layer of purified organic semiconductors – Zn, Pb and Fe Phthalocyanines, deposited by organic molecular evaporation in high vacuum chamber (10-5 Pa, dep. Rate ~ 0.1-3nm/min, substrate temp. 20 – 300 °C). The temperature of deposition source and substrate was selected for each substance so as to achieve optimal growth rate and to avoid thermal decomposition of materials. In the next step CW laser depositions were carried out from these substrates. The deposition apparatus include micro CNC machine (minimal step adjustable to 300 nm) equipped with the semiconductor laser (405 nm, 10 - 50 mW, spot 6 microns) in continual mode and focusing optics. The distance between source substrate and target (i.e. glass, silicon or alumina sensor substrates) was varied between 1-100 micrometers. Deposition process was held in an inert gas (Argon, Nitrogen) at atmospheric pressure. Morphology and microstructure were studied by optical, electron microscopy and AFM. Chemical composition of deposited structures was studied by FTIR and compared with that of source substances. It was proved that chemical structure of all chosen substances is not affected by this deposition technique. The best lateral resolution of prepared structures was obtained for source layer thickness of 100-150 nm. Employing our technique we are able to achieve precise and reproducible laser transfer of organic semiconductors to the target sensor substrate with lateral structural resolution of 14 microns.
We can make an assumption that our technique could be used also for other organic semiconductors used in gas sensors which can be deposited by organic molecular evaporation.