Reactive sputtering of Fe2O3 thin films by high power pulsed plasma systems
2012 (English)Conference paper, Poster (Refereed)
Semiconductor oxide thin films of Fe2O3 were deposited by reactive sputtering in a high power pulse magnetron and in a pulsed hollow cathode plasma jet sputtering system. Properties of deposited Fe2O3 were investigated for photocatalytic water splitting applications. Fe2O3 provide a potential to capture a relatively significant portion of the available solar light due to lower band-gap energies. The first system used in this study was the high power pulsed magnetron sputtering system (HIPIMS) employing metallic target of pure iron with outer diameter 50 mm and working in a gas mixture of Ar and O2. Influence of different magnitudes of the applied pulsed power and pulsing frequency on the formation of crystalline structure, physical properties and photocatalytical properties was investigated. The maximum pulsed current density used in our reactive HIPIMS magnetron system was ≈ 5 A/cm2. Oxide Fe2O3 thin films were deposited also by a low pressure DC pulsed hollow cathode system. The metallic hollow cathode with internal diameter 5 mm and length 30 mm was sputtered in argon plasma flow and reactive gas oxygen was supplied directly to the reactor. The hollow cathode discharge was supplied from the DC pulsed power supplier working in high power pulsed mode. The maximum attained pulsed current density in our hollow cathode discharge was approximately ≈ 3 A/cm2. The main advantage of this system was the high deposition rate which was nearly independent on the amount of used oxygen in the plasma. A plasma diagnostics was carried out in all the investigated systems. The most important was measurement with various forms of quartz crystal microbalance QCM with several types systems of grids. These systems were used to determine ionization fraction of sputtered and reactively sputtered particle fluxes to the substrate under different deposition conditions of these oxide thin films. The higher ionization fraction of sputtered particles was found for higher current densities in the pulse. In the HIPIMS magnetron, the maximum of ionization fraction of reactively sputtered particles was found around ≈ 60-70% for 5% duty cycle of pulsing frequency. The maximum ionization fraction of sputtered particles in the reactive pulsed hollow cathode system was usually lower than in the investigated reactive HIPIMS magnetron system.
Place, publisher, year, edition, pages
Manufacturing, Surface and Joining Technology
Research subject Engineering Science with specialization in Electronics
IdentifiersURN: urn:nbn:se:uu:diva-190022OAI: oai:DiVA.org:uu-190022DiVA: diva2:582827
RSD2012, Reactive Sputter Deposition symposium, December 2012, Ghent, Belgium