Dresden 2006 – wissenschaftliches Programm

Bereiche | Tage | Auswahl | Suche | Downloads | Hilfe

O: Oberflächenphysik

O 10: Semiconductor surfaces and interfaces

O 10.7: Vortrag

Montag, 27. März 2006, 16:30–16:45, PHY C213

Photothermally induced dehydroxylation on surface-oxidized silicon substrates: A simple means for the fabrication of submicron-structured hydrophilic/hydrophobic templates — •Nils Hartmann, Thorsten Balgar, Steffen Franzka, and Eckart Hasselbrink — Universität Duisburg-Essen, Fachbereich Chemie, Universitätsstr. 5, 45141 Essen

Patterns with alternating hydrophilic and hydrophobic domains are widely used to control and study processes at surfaces in many fields of material science. We recently reported a laser-assisted procedure for the fabrication of hydrophobic patterns on hydrophilic, surface-oxidized silicon substrates [1]. Local irradiation with a highly focused laser beam at a wavelength of 514 nm results in photothermal dehydroxylation and converts the affected surface areas from hydrophilic to hydrophobic. The patterns are stable for weeks or longer, even if the samples are stored at ambient conditions. Contrary to ordinary avenues to hydrophilic/hydrophobic patterns no coating is required. This makes the procedure extremely simple and robust. Routine patterning can be carried out over large areas at fast writing speeds under ambient conditions. At a focal spot diameter of about 2.5 µm, hydrophobic lines with a width down to 0.4 µm are prepared. The laterally varying hydrophilicity provides an opportunity to further functionalize the surface. In particular, as shown here, the patterned substrates represent suitable templates for the directed self-assembly of organic monolayers.

[1] T. Balgar, S. Franzka, E. Hasselbrink, N. Hartmann, Appl. Phys. A, in press.