High resistivity AlO x thin films deposited by a novel two-step sputtering process

Abstract

A novel sputter deposition technique has been developed in which the first layer and the second layer are controlled independently. This technique has been used to prepare AlO x thin films as dielectric passivation layers. A very thin film is deposited first with the substrate not exposed to the plasma region, while the remaining part is deposited in the plasma region. This new technique produces high resistivity AlO x films 500 nm thick of wide area, even on rough substrate surfaces. This result indicates that it is necessary to optimize the energy and flux of bombarding ions or neutral atoms in the first-layer formation and in the second-layer formation independently for densification of the films. The applicability of this approach could be extended to the deposition of other materials.