Preparation And Optical Properties Of Nanocrystalline Silicon Carbide Films With Pulse Laser Deposition

Amorphous SiC (a-SiC) films are deposited by pulse laser deposition (PLD)with low laser energy fluence at low substrate temperature. The characteristics of crystallized SiC films by thermal annealing in vacuum and laser annealing respectively are studied. The morphology, microstructure and optical properties of as-deposited and annealed SiC films are characterized by atomic force microscopy (AFM), Raman scattering and ultraviolet-visible transmission spectroscopy (UV-VIS Transmission). After thermal annealing in vacuum at above 850癈, a-SiC films transform to nanocrystalline SiC. With thermal annealing temperature increasing, percentage of transmission and optical band-gap of SiC films increase. The crystallinity of SiC films enhances with increasing annealing temperature. The optical properties of annealed SiC films are analyzed by the quantum confinement effect. The effect of different laser fluence on the properties of laser-annealed SiC films is studied. Using the melting model, the laser-annealing crystallization meehnism of a-SiC films is investigated. Nanocrystalline SiC oriented growth is obtained at low temperature by Fe-induced crystallisation technique. Using the least energy principle, the mechanism of Fe-induced oriented growth of nanocrystalline SiC is analyzed.