Thin-Film Formation by Laser-CVD

Abstract

Light-assisted CVD (chemical vapor deposition), and in particular laser-CVD, open up new possibilities in thin-film fabrication. Laser light permits one to selectively generate high concentrations of atomic or molecular intermediate species that are present either not at all or only in small equilibrium concentrations in standard CVD using the same precursor molecules. Thus, laser-CVD enables one to study new reaction pathways and altered kinetics in thin-film growth. Lasers are often preferred over high-intensity lamps, at least in fundamental investigations, because of their high experimental versatility related to their intensity, monochromaticity, tunability, and directionability. In particular, at parallel incidence to the substrate surface, lasers permit pure gas-phase excitation. With perpendicular laser-beam irradiation, gas and surface excitations, including adsorbed layers, are important. The different irradiation geometries employed in large-area laser-CVD have been described together with Fig. 5.2.3.