Improvement on Plasma Intensity Uniformity in Rectangular DC Magnetron Sputter by Optimizing Structures of Substrate Electrode

Abstract

DC magnetron sputtering is widely used for thin film deposition in the field of displays. By adding magnet arrays to a large rectangular magnetron sputtering system, while the ionization and deposition rate are increased, the film properties can be nonuniform, and the local target erosion rate can be increased. Film properties strongly depend on uniform plasma density and energy. Although the ferromagnetic shield has been used to decrease the magnetic field locally, the plasma remains nonuniform at the corners of the rectangular shape target. In this study, a plasma simulation was conducted to analyze the plasma distribution in a DC magnetron sputtering system. The plasma uniformity was improved by optimizing the thickness and shape of the substrate electrode, carefully controlling the distance between the target and substrate electrode based on Paschen’s law, leading to the reduction of local high plasma intensity.