Sputtering refers to energetic particle bombardment of solid surfaces (targets), the solid atoms (or molecules) is emitted from the surface, and deposited onto the substrate. It is a kind of physical vapor deposition. Positive ion sputtering is generated by a gas discharge in the electric field of the high-speed bombardment as a cathode target, the target of the atom or molecule by collisions generate momentum transfer, so that the target surface atoms or molecules escape and lakes product to be plated of the workpiece surface to form the desired film.
Sputtering method is divided into direct-current sputtering method, RF sputtering, magnetron sputtering, reactive sputtering, intermediate frequency sputtering pulse sputtering, bias sputtering, ion beam sputtering and the like. The deposition rate by magnetron sputtering is high and low pressure working gas and other unique advantages make it become the most widely used method of sputter deposition.
RF sputtering and magnetron sputtering method are widely applied to producing WO3 thin film.
Tungsten oxide thin film prepared by sputtering method has the advantages of fast film-forming speed, high purity, high density, and good bonding and strength, etc. By controlling the atmosphere pressure and temperature to obtain high performance WO3 thin film, but the process is too complicated to control, the thickness of prepared thin film is uneven, the high manufacturing cost limits its application.