Sputter Rate Distribution and Compositional Variations in Films Sputtered from Elemental and Multi-Element Targets at Different Pressures
2014 (English)In: International Journal of Materials Science and Applications, ISSN 2327-2635, Vol. 3, no 2, 29-36 p.Article in journal (Refereed) Published
We report on the quantitative dependence of the deposition rate during magnetron sputtering as a function of the atomic mass, processing pressure and substrate location relative to the target. Targets made of four different materials (C, Al, Ti and Ta), ranging from very light to rather heavy atomic masses, were investigated theoretically initially to determine the deposition rate distribution of the sputtered atoms. In the second part, targets made of different combinations of these materials (Ta/C, Ta/Al, Ta/Ti and Ti/Al) were sputtered to investigate the compositional variations of deposited films. The different targets were sputtered at both low (0.27 Pa) and high (2.7 Pa) pressures, and both the deposition rates and compositions were determined at four different locations in the chamber. Further, Monte Carlo simulations were performed for the sputtered atoms in a simplified model of the vacuum chamber. Simulation and experiments are in adequate agreement and show a significant influence of the processing pressure on the deposition rate in various locations of the chamber. This effect is different for different target compositions and may sometimes result in very large compositional variations in films sputtered from segmented multi-element or alloy targets. Transport phenomena of the sputtered particles are also discussed based on a ballistic or diffusion-like process, depending on the sputtering pressure, mass and size of the sputtered atom as well as location in the deposition chamber. Since the materials studied range from light to heavy and the processing pressures cover the values where sputtering normally takes place, the results in this work can be extrapolated to predict the deposition profiles and compositional gradients for arbitrary material combinations and processing pressures.
Place, publisher, year, edition, pages
2014. Vol. 3, no 2, 29-36 p.
Condensed Matter Physics Nano Technology Other Materials Engineering
Research subject Engineering Science with specialization in Electronics
IdentifiersURN: urn:nbn:se:uu:diva-220583DOI: 10.11648/j.ijmsa.20140302.14OAI: oai:DiVA.org:uu-220583DiVA: diva2:705691