Investigation of ionized metal flux fraction in HiPIMS discharge with Ti and Ni target
2013 (English)Conference paper, Presentation (Refereed)
In deposition of thin film, energetic bombardment during the film growth has a strong impact on the film growth with respect to the film density, adhesion, or internal stresses. Since the energy of impinging ions can be readily controlled by a substrate bias, various means of increasing the ionization degree in sputtering have been investigated. In High Power Impulse Magnetron Sputtering (HiPIMS), high degree of ionization of the sputtered material may be achieved thanks to the high peak powers and thus high plasma densities.
In this contribution, the ionized metal flux fraction, the ratio between ionized and neutral metal species, arriving to the substrate in HiPIMS was analyzed. A combination of retarding field analyzer and quartz crystal microbalance (QCM) was used. The QCM sensor can measure the deposition rate from ions and neutrals separately by changing the applied bias voltage allowing for fast determination of the total ionized fraction of material flux to the substrate.
Two target materials, Ni and Ti were studied, in the case of Ti in both nonreactive (Ar) and reactive (Ar+O2) atmosphere. Measurements with the QCM analyzer showed an ionized fraction of up to 50% for Ni. Somewhat higher values, exceeding 60%, were measured for Ti. In this case, shorter on times lead to higher ionized fraction at the same deposition rate and average discharge power.
In reactive sputtering of Ti, substantially higher ionized fraction was observed in the oxide mode as compared to the metal mode. Already at lower values of the peak power, there was a significant fraction of Ti ions in the oxide mode. The results are very important for thin film synthesis because show process conditions for ion assisted depositions.
Place, publisher, year, edition, pages
Manufacturing, Surface and Joining Technology
Research subject Engineering Science with specialization in Electronics
IdentifiersURN: urn:nbn:se:uu:diva-208522OAI: oai:DiVA.org:uu-208522DiVA: diva2:652898
XXII INTERNATIONAL MATERIALS RESEARCH CONGRESS 2013 11 – 15 August, Cancún, Mexico