Active process control of reactive sputter deposition

Control of the density, composition, ionisation rate and arrival energy of species is one of the main objectives of research in the development of reactive magnetron sputtering. The deposition of the latest generation of multilayer and multi-component coatings requires the independent control of deposited flux parameters using fast response and reliable control systems. A review of recent advances in process control showed the potential of techniques such as unbalanced magnetron sputtering in a closed magnetic field configuration, thermionically enhanced deposition and closed loop control with optical gas and metal plasma emission monitoring. These techniques were combined in an active control system. Special software was used to provide automatic computer aided process control in the deposition of multilayer and multi-component coatings. The system has been evaluated on a range of refractory and DLC coatings and recommendations on process control are given.