Preparation of metal nitride and oxide thin films using shielded reactive vacuum arc deposition

Abstract

Various metal nitride and oxide thin films were prepared using a shielded reactive vacuum arc deposition. The cathode materials used as metal ion sources were Al, Ti, Cu, Cr, and Zn. These nitride and oxide films were deposited in pure N 2 and O 2 gas flows, respectively. First, the films were deposited for a short period by both non-shielded and shielded methods, and the macrodroplet appearance on the films was compared. Macrodroplets were reduced remarkably, to less than one-hundredth for Al in N 2, Zn in N 2 and Al in O 2. For Ti in N 2, Cr in N 2, Cu in N 2, Ti in O 2, and Zn in O 2, the macrodroplets were reduced by one-third, although they were not reduced for Cr in O 2. X-ray diffraction analysis revealed that crystallized films were AlN, TiN, CrN, Cu 3N with Cu, CuO, and ZnO, and that amorphous films were Al 2O 3, TiO 2 and Cr oxide. Zn 3N 2 were weakly synthesized in Zn metal film. AlN, Al 2O 3 and TiO 2 films were very transparent with refractive indices of 2.1, 1.6 and 2.3 at 500 nm, respectively. ZnO film also exhibited good transparency.