High-rate reactive dc magnetron sputtering of ZrOx coatings

ZrOx coatings were synthesized using reactive d.c.-magnetron sputtering of a Zr metal target in argon-oxygen gas mixtures. Pulsed-d.c. power supplies were able to stop arcing on the cathode and on the substrates. The structure and properties of the ZrOx films were affected by several of the reactive sputtering process variables such as substrate bias and oxygen partial pressure (P-o2) and by the substrate materials. With automatic feeedback control of P-o2, a series of ZrOx coatings, where 0 less than or equal to x less than or equal to 2, were deposited onto various substrates. With increasing P-o2, the deposition rate decreased, and the phases of the coatings changed from Zr metal, to Zr-O solid solution, to mixtures of Zr-O and monoclinic ZrO2 (m-ZrO2), and finally to m-ZrO2. The hardness of the ZrOx films ranged from 6 to 20 GPa. Highly textured m-ZrO2 films, with either (-111) or (002) preferred orientation, were deposited. The highest m-ZrO2 rate was 240 nm min(-1), which is 75% of the Zr metal deposition rate.