How to run a reliable reactive HIPIMS process over a target lifetime

While reactive high-density plasma processes, like HIPIMS, are more and more adapted in industrial plasma applications, a reliable and stable control technique is crucial for securing deposition parameters in production processes. For example, stabilizing deposition rate and layer properties over the complete lifetime of the target will make HIPIMS production more effective and competitive regarding product quality and production costs. Especially HIPIMS applications are facing the challenge, that the target erosion modifies the magnetic field strength in front of the target, what in turn has a dramatic impact on peak current and ionization. With the combined control technique based on spectroscopic data and electrical pulse data, HIPIMS production processes can be controlled despite long-term drifts such as target erosion or change of chamber conditions. By combining the measurement of pulse current and pulse voltage with the spectroscopic plasma monitoring technique, independent control of degree of ionization and reactive gas flow can be realized, thus securing layer density and stoichiometry at the same time. While the spectroscopic data reveals mainly information about the gas composition, the analysis of the pulse form provides additional information about ion density and reactive operation mode (metallic, transition, poisoned). Evaluating either data in a combined control algorithm, opens the door for establishing a long-term process control for productions lines. Examples of coating applications addressing target erosion, changing chamber conditions, and different magnetic cathode conditions will demonstrate the capabilities of the combined control technique for long-term stabilization against process drifts