SPUTTER-DEPOSITION OF YTTRIUM-OXIDES

The yttrium-oxide phase diagram contains only one equilibrium compound, a Y2O3 cubic structure. The process of reactive sputter deposition is used to synthesize previously unreported, yttrium-rich oxide compounds. A planar magnetron is operated in the direct-current mode using a working gas mixture of argon-20% oxygen. For low sputter gas pressure and flow conditions, the yttrium content of the coating is directly controlled as a function of the applied target power, i.e., the deposition rate. The composition and structure of the coatings are characterized using Auger depth profiling and x-ray diffraction. A continuous series of compounds are formed with an orthorhombic crystal structure for concentrations ranging from 40 to 75 at. % yttrium.