Magnetic field optimization for high power impulse magnetron sputtering

High Power Pulsed Magnetron Sputtering (HPPMS) or High Power Impulse Magnetron Sputtering (HiPIMS) is a promising Physical Vapor Deposition technique with several advantages over DC Magnetron Sputtering (dcMS). HiPIMS has gained a lot of interest in the recent years from the coating industries. The films that are deposited by HiPIMS technique are of superior quality and their properties can be tailored for various applications. The main challenge that obstructs its broader implementation in industry and its use by researchers is its lower deposition rates compared to dcMS. Magnetic field profile on the magnetron target surface defines plasma properties and potential distribution in the space above the target region. In this work, the magnetic field profile on the top of the target surface is modified to allow more ions to escape from the electric potential trap contributing to the increase in deposition rates. The "ε" magnet pack which was developed based on the idea of modifying the magnetic field configuration demonstrated increased deposition rates in HiPIMS compared to conventional magnet pack arrangement. In order to keep the deposition rates high as in "ε" magnet pack and improve coating uniformity on substrates, a cylindrically symmetric "TriPack" magnet pack was developed based on the design solutions from "ε" magnet pack. The "TriPack" magnet pack gives higher deposition rates in HiPIMS compared to conventional magnet pack with superior uniformity. A gated ICCD camera was used to investigate the moving localized "ionization zones" in the TriPack. Langmuir probe and ion fraction measurements were also carried out to understand the behavior of high current pulsed discharge in this new magnetic field configuration. Particle flux and critical current density models were developed to explain the reason behind increase in HiPIMS deposition rates and absence of ionization zones in this new magnetic configuration.Ope