Newly designed equipment to deposit thin films of Al2O3 by the aerosol deposition method (ADM) at room temperature is reported. It was found that a gas flow rate above a certain minimum was necessary to deposit thin films of Al2O3, The films has the same crystal structure as the raw material. A certain amount of time was required for the average diameter of the particles ejected from the nozzle to become constant. The surface roughness increased as the gas flow rate increased. Furthermore, the surface roughness showed a tendency to asympototically approach a value of approximately 23nm. The absorption coefficient of optical light for the films depended on the wave length and exponentially decreased with increasing wavelength in the wave length range of 300-900 nm, The average breakdown electric field for the Al2O3 films deposited using ADM was approximately 66kV/mm, about 3 times larger than that for bulk Al2O3 produced by sintering.
