Sputtering of dielectric single layers by metallic mode reactive sputtering and conventional reactive sputtering from cylindrical cathodes in a sputter-up configuration

In today's sputtering solutions in the field of precision optics, usually planar targets are used which suffer from inhomogeneous surface erosion. This leads to a drift in uniformity over time, higher material costs and in the case of reactive sputtering an increased tendency to form arcs which cause particle generation. In this paper an approach is presented that overcomes the disadvantages planar magnetrons present to sputtering. A rotating turntable coater was equipped with two dual cylindrical magnetrons in a sputter-up configuration. Thin films prepared by metallic mode reactive sputtering as well as reactive mid-frequency sputtering were investigated. Properties of Ta2O5 and SiO2 such as film stress, optical density and surface roughness are discussed. It is shown that the coatings are suitable for applications in precision optics.