A method for forming thin films of dielectric material which exhibit improved quality and piezoelectric response, which are formed in a DC magnetron reactive sputtering system. The dielectric material is deposited onto a substrate, and the deposition is interrupted before a highly insulating film is grown on the chamber interior. Then, the reactive gas is removed from the chamber and replaced with an inert gas, and a layer of metal is deposited on the chamber interior. This deposition of a metal layer conceals the highly insulating film on the chamber interior thereby improving the quality and piezoelectric response of the dielectric thin films. During the step of depositing a metal layer, the deposited substrate is shielded in order to prevent metal from being deposited on the substrate. Then, the deposition of dielectric material on the substrate and deposition of the metal layer on the chamber interior is repeatedly alternated until a desired thickness of the dielectric thin film has been reached.