IMPROVEMENT OF THE CRYSTALLINE QUALITY OF AN YTTRIA-STABILIZED ZIRCONIA FILM ON SILICON BY A NEW DEPOSITION PROCESS IN REACTIVE SPUTTERING

A heteroepitaxial yttria-stabilized zirconia (YSZ; (ZrO2)1-x(Y2O3)x) film is difficult to grow on Si by reactive sputtering with Ar + O2 gases, since the bare Si surface is easily oxidized by plasma radiation or excited oxygen. In order to overcome this difficulty. a very thin metallic Zr1-xYx film is deposited on the Si substrate by sputtering with Ar gas before depositing the YSZ film. This new deposition process can improve the crystalline quality of the YSZ film and produce a heteroepitaxial YSZ film on Si even in reactive sputtering. It was also found that the thickness and deposition temperature of the metallic film strongly influenced the crystalline quality of the YSZ film on Si, their optimum values being about 0.4 nm and 800-degrees-C respectively.