Options
2019
Conference Paper
Titel
Combined control of ionization and stoichiometry in reactive highly ionized processes for production lines
Titel Supplements
Abstract
Abstract
While reactive high-density plasma processes, like HIPIMS, are more and more adapted in industrial applications, a reliable and stable control technique is crucial for securing deposition parameters in production processes. In reactive HIPIMS applications, the chemical composition (i.e. layer stoichiometry) and the film physical properties like density are dpending on the gas composition of metal to reactive species and the degree of ionization. However, these parameters are influencing each other in highly ionized plasmas and thus, a single control on either gas flow or peak current is not sufficient to run a stable production process. Especially with progressing target erosion, the work point will shift and in the worst case run out of any tolerance without proper control. 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 chemical composition and physical film properties 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 for different layer materials and porperties will demonstrate the capabilities of the combined control technique for tuning and controlling the plasma properties to secure constant layer properties.