Sustainability issues in sputtering deposition technology

Sputtering involves ejection of atoms from a surface upon impingement by energetic ions generated by a plasma. The plasma is created by a large potential difference (2 kV) between the cathode and anode in vacuum and it contains both electrons and ions. These ions get accelerated towards the target (cathode) to eject the adatoms of the target that deposits onto the substrate to form a thin film. The deposition rate of sputtering depends on the plasma density; higher plasma density increases the ions involved in bombardment of the target. Like any other manufacturing process, sputtering technology is associated with sustainability aspects such as control of the plasma density, input potential voltage and current, efficiency of sputtering (sputtering yield, mean free path), cooling system (input water and cooling power), temperature (substrate and target) and maintenance of the sputtering systems. Issues of production rates, automation and mass production are also very important for sustainable manufacturing process including sputtering technology. Optimization of the process parameters for deposition of specific films should consider these sustainability issues. This article highlights these sustainable issues with an effort to evaluate the sustainability of sputtering as a thin film deposition technology using HHV TF500 Thin Film Deposition System as a case study.