Berlin 2008 – wissenschaftliches Programm

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CPP: Fachverband Chemische Physik und Polymerphysik

CPP 34: POSTERS Polymerphysics

CPP 34.34: Poster

Donnerstag, 28. Februar 2008, 17:00–19:30, Poster A

Influence of substrate temperature on pulsed laser deposited PMMA films — •Britta Lösekrug, Susanne Seyffarth, Andreas Meschede, and Hans-Ulrich Krebs — Institut für Materialphysik, Universität Göttingen, Friedrich-Hund-Platz 1, D-37077 Göttingen

Poly(methyl methacrylate) (PMMA) thin films are important for applications e. g. as coating materials and in microelectronics. Here pulsed laser deposition (PLD) at a wavelength of 248 nm is used with low laser energy densities slightly above the deposition threshold of PMMA (between 80 and 160 mJ cm⁻²). Under these conditions at room temperature thin films can be produced which are completely smooth and show no droplets at all [1].

In contrast, for higher substrate temperatures above the glass transition (at 110 ^∘C) a dewetting of PMMA thin films on Si(111) substrates occurs. Additionally, an increased hardness of these PMMA films compared to films deposited at room temperature is observed. So the properties of PMMA films change with substrate temperature during deposition. It can be shown by infrared spectroscopy (FTIR) and size exclusion chromatography (SEC) that the chemical composition of the PMMA films is still intact up to 200 ^∘C, while the chain lengths are reduced compared to the starting material. At still higher temperatures the deposited material begins to evaporate.

[1]B. Lösekrug, A. Meschede, H.U. Krebs, Appl. Surf. Sci. 254 (2007) 1312