GROWTH FRONT ROUGHENING OF ROOM TEMPERATURE DEPOSITED OLIGOMER THIN FILMS

摘要

Growth front scaling aspects are investigated for PPV-type oligomer thin films vapor-deposited onto silicon substrates at room temperature. For film thickness d～15-300 nm, commonly used in optoelectronic devices, correlation function measurement by atomic force microscopy yields roughness exponents in the range H=0.45+-0.04, and an rms roughness amplitude which evolves with film thickness as a power law σ∝ d~β with β=0.28+-0.05. The non-Gaussian height distribution and the measured scaling exponents (H and β) suggest a roughening mechanism close to that described by the Kardar-Parisi-Zhang scenario.