J. Eur. Opt. Society-Rapid Publ. 21, 24( 2025) 237
Figure 3. Schematically drawn the tool with the sputter and plasma sources on top of it facing downwards on the table( left side). The opened tool with the rotating substrate table and the sources folded away( right side).
Figure 4. The diagram shows the process for producing QNL schematically. Due to the continuous process, a high rate and also a very stable behavior can be achieved.
Each rotation allows the layer to grow incrementally as the substrates pass under the source. The growth rate of this layer can be controlled either through calculations based on known rates or via optical monitoring, here the Evatec GSM1102 is used with both monochromatic and broadband monitoring algorithms. For QNL production, where two different materials are required, we operate two sources simultaneously. This setup necessitates stabilizing the system to prevent process drift. By doing so, we can deposit one layer of SiO 2 and one of Ta 2 O 5 with each table rotation, see Figure 4. The ratio between the two materials is adjusted by modifying the power supplied to the respective sputter sources. Additionally, the layer pair thickness can be fine-tuned by altering the rotation speed of the table; faster rotations yield thinner layers which amplifies the impact on the band gap. The ability to maintain a continuous process while depositing material from both sources simultaneously eliminates interruptions for alternating layers. This approach not only achieves a significantly higher deposition rate but also ensures a stable and consistent process. As a result, we can reliably produce uniform individual layers. This efficiency makes the production of QNL highly costeffective, enabling its use as a standalone material in complex coating designs.
2.3 Material properties
We tested a variety of processes with different material ratios. All samples were coated for a duration of 900 s each, regardless of their deposition rate. For some selected