O. Hernandez-Rodriguez¹, R. Ortiz¹, E. Zuza¹, V. Bellido-Gonzalez², I. Quintana¹, E. G-Berasategui^1
1Tekniker, Eibar, Spain
²Gencoa Ltd, Liverpool, United Kingdom
Reactive magnetron sputtering is one of the fundamental techniques for the industrial fabrication of functional oxide coatings. The literature provides extensive knowledge on discharge behaviour, target poisoning, hysteresis phenomena, and thin film growth mechanisms. However, the large majority of reported results are obtained under laboratory scale conditions. In the context of industrializing electrochromic functional coatings, process development still relies heavily on extensive trial-and-error iterations, leading to high consumption of time and resources and limiting the rapid deployment of new coating systems. Transferring laboratory based knowledge to industrial coaters therefore remains a major challenge, as scaling the process to large area magnetrons inherently modifies the plasma state, reactive gas dynamics, and metal oxygen balance at the target surface.
This work establishes and validates, at industrial scale, a methodology for the identification, acquisition, and control of plasma process signals using optical emission spectroscopy (OES) combined with closed-loop process control. The approach is applied to the deposition of electrochromic NiV_xO_y coatings using different selected process control points and is supported by multiscale characterization to correlate plasma signals with microstructural and optical properties.
The results demonstrate that OES control enables a consistent transfer of deposition conditions from laboratory to industrial systems, preserving the main optical and structural trends of the coatings despite substantial differences in equipment configuration and deposition rates. Compared to conventional flow-controlled operation, the proposed strategy significantly improves process reproducibility and reduces the number of experimental iterations required to reach stable operating conditions and functional performance.