In an aerosol deposition method, factors affecting the surface roughness of Al2O3 thick films deposited on Cu substrates at room temperature were studied to propose guidelines for the growth of aerosol-deposited ceramic films with a flat and smooth surface morphology. The surface roughness and deposition rates of aerosol-deposited Al2O3 films strongly depended on the initial surface roughness of substrates. Even oil flat substrates, however, their surface roughness became worse with an increase of their film thickness. Through the investigation of surface morphologies from the initial growth stages to the final, it was revealed that the deterioration of the surface roughness of Al2O3 films oil flat substrates was substantially associated with the evolution of craters; during the deposition. The fundamental cause of these results was explained by impact of hard Al2O3 particles above 1 mm in size by comparison with the surface morphologies of the aerosol-deposited Ag or polyimide films.

Keywords: Aerosol deposition Method; Room temperature; Surface roughness; Crater; Cu substrate; Al2O3 Film