Adam Obrusnik¹, Gayatri Rane², Radoslav Brunovsky¹, Philipp Dürrenfeld², Martin Kubecka¹, Kristina Tomankova¹, Uwe Krause², Denis Shaw^2
1PlasmaSolve s.r.o., Brno, Czech Republic
²Advanced Energy Industries, Customer Solutions Lab, Karlstein am Main, Germany
Physical vapor deposition (PVD) techniques, particularly in large area coaters such as glass and roll-to-roll (R2R) coating systems, depend significantly on the understanding and control of plasma dynamics for optimal film deposition. The response of the plasma to applied electrical power is crucial, considering the low tolerances in film thickness and film properties variations that the large-area coating industry aims for. This study employs 2D physics-based plasma simulations to investigate the impact of pulse shape and anode placement on plasma behavior and film properties produced in these coaters.
At the 2024 SVC TechCon, Advanced Energy and PlasmaSolve demonstrated that a high-fidelity physics model can explain the key differences between two very distinct types of plasma-driving waveforms - dynamic reverse pulsing (DRP) and symmetric bipolar pulse-dc (BP). By combining simulation and experimental insights, we were able to demonstrate that by proper anode placement, the energy efficiency of the DRP process can be increased by approximately 10 %. Furthermore, the model helped to explain why the BP waveform delivers systematically higher heat load on the substrate.
In this contribution, we present an extension of the study by comparing reactive sputtering of silicon nitride using a sine wave generator and a bipolar pulsed-dc generator. Once again, we investigate how the waveforms impact the plasma density, ion bombardment on the substrate, the heat load on the substrate and correlate these with the experimentally observed film growth dynamics.
Moreover, we quantify the impact of pressure and the geometrical layout of the coater on overall material utilization in a drum coater. We show that the tilt angle, operating pressure, and the throw distance impact the utilization of cathode material.
This comparative study enhances the ability to control film properties through precise manipulation of process variables, offering insights that are crucial for advancing PVD technology in industrial applications. How the detailed plasma simulation interfaces with other types of models such as the MatSight 3D Uniformity App that can predict coating thickness distribution on geometrically complex features is also discussed.