A New Generation of Flexible Power Supplies for Dual Magnetron Sputtering

The deposition of elemental and compound conductive materials and dielectrics by dual magnetron sputtering is a standard technique for industrial thin film layers. Applications include OLED, passivation layers, solar cell active layers, low-emissivity coatings on glass, and web coating of plastic films. A new generation of power supplies with configurable powers from 30 kW to greater than 200 kW has been developed for large area dual magnetron sputtering applications. They have settable frequency, duty cycle, and peak voltage with the possibility of influencing film properties such as crystallinity, morphology, density, index of refraction and stress. Selectable fixed frequency enables operation of the process at the lowest possible frequency, with highest deposition rate, since rate generally increases with decreased frequency. Control of power to each individual magnetron by changing duty cycle enables comparatively more power to be delivered to one of the targets to compensate for differences in remaining target material, or for reduction of arcing when one target is arcing more than the other. In this new generation, arc energy is dramatically reduced, which enables lower defect rate in deposited films. This paper describes application of this new technology for increasing flexibility of coating lines and extending process performance.