Scilab/Xcos-based design and modeling of a DC power supply for low-cost plasma treatments

• Main Authors: Mandala, S. H. S., Januar, M., Grady, M., Sejati, P., Liu, K.-C.
• Format: Conference Proceeding
• Language: English
• Subjects: Block diagrams; Capacitors; Contact angle; Direct current; Electric contacts; Electric power supplies; Glass substrates; Hydrophilicity; Inductors; Ion bombardment; Laboratories; Low cost; Nylon; Open source software; Parameter modification; Plasma; Plasma currents; Power supply; Prototyping; Resistors; RLC circuits; Silica glass; Silicon dioxide; Thin films; Time measurement; Topology; Waveforms; Wettability
• ISSN: 0094-243X; 1551-7616
• DOI: 10.1063/5.0213165

Plasma treatment offers many advantages in thin-film processing and has become a leading technique for modifying thin film properties in a wide variety of applications. Power supply is a key element to operate a plasma treatment system, yet, low-cost power supply systems are still commercially limited in the market, which restricts the use of plasma treatment in small-scale laboratories or industries. Herein, we proposed a simple topology of the direct current (DC) power supply to develop an affordable reactive plasma-treatment system. The electrical circuit of the proposed power supply is represented in the block diagram models, and it was simulated using open-source Scilab/Xcos software and experimentally tested by prototyping the power supply. The topology of the power supply is designed by adopting a simple resistor-inductor-capacitor circuit, which plays an important role in maintaining a higher plasma current waveform and regulating the plasma current characteristics. In particular, adjusting the resistor component in the circuit can amplify the positive peak of the plasma current, thereby increasing the ion bombardment on the substrate surface. Furthermore, a decrease in the value of the capacitor or an increase in the value of the inductor can produce a clear negative peak of the plasma current with more waveform oscillations, which is beneficial for reducing the accumulation of charge on the surface during the process. As a result, the optimized parameters can speed up the plasma treatment process without suffering from arcing effects. In addition, the performance of the proposed power supply in the surface modification was analyzed using contact angle measurements. We found that increasing the exposure time can change the wetting characteristics of the silica-glass and nylon-mesh substrates to be more hydrophilic. By performing plasma treatment on the samples for 15 min, the wettability of the silica substrate became more hydrophilic. At the same time, the wettability of the nylon-mesh substrate remarkably changed from hydrophilic to superhydrophilic and superoleophilic. This work demonstrates a simple approach to designing DC power supplies for low-cost plasma processing systems using open-source software, which can be used to develop small-scale laboratories or industries.