Amorphous thin poly(bisphenol A carbonate) films are prepared on Si, SiO2, GaAs, and spin cast polycarbonate substrates by condensation from vapor. Surface morphologies are investigated using scanning force microscopy with focus on the substrate-film interface formation. Except for polycarbonate substrates, where smooth surfaces are observed for all film thicknesses, a change from rough discontinuous surfaces for very thin films to smooth homogeneous surfaces for thicker films appears due to dewetting effects. Utilizing Fourier transform infrared spectroscopy, size-exclusion chromatography, and mass spectrometry, we find that the bond topology stays mostly intact during evaporation, while the molecular weight as well as the chain length is reduced.

The early stages during low temperature vapor deposition of organic materials onto inorganic substrates are frequently characterized by surface pattern formation on a characteristic length scale, accompanied by dramatic roughening, while these structures level at higher film thicknesses. Unexplainable by traditional liquid-state dewetting scenarios, we employ a combined experimental/modeling study to track down the underlying physics using poly(bisphenol A carbonate) (PC) on GaAs (100) as a model system. We present a minimum continuum model, which incorporates only material deposition and chemical potential driven surface diffusion as material processes, whose numerical solution is capable of reproducing key experimental features.

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Surface evolution during the vapor deposition of chainlike model polymers onto a substrate is investigated with the help of Monte Carlo simulations. Polymer chains are deposited as linear chains of inseparably bonded particles and subsequently relax via a reptation type of dynamics. We investigate the impact of processing parameters on kinetic roughening and find a crossover from single particle behavior to continuous growth behavior in early growth stages. The continuous growth behavior is characterized by a growth exponent β=0.20±0.02 and a roughness exponent α=0.38±0.02 for most preparation conditions. In the high thickness regime a strong roughening and concurrent structural change of morphologies is observed.

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