Influence of chemical composition and deposition conditions on microstructure evolution during annealing of arc evaporated ZrAlN thin films
2012 (English)In: Journal of Vacuum Science & Technology. A. Vacuum, Surfaces, and Films, ISSN 0734-2101, E-ISSN 1520-8559, Vol. 30, no 3, 031504- p.Article in journal (Refereed) Published
The influence of substrate bias and chemical composition on the microstructure and hardness of arc evaporated Zr1−xAlxN films with 0.12 < x < 0.74 is investigated. A cubic ZrAlN phase is formed at low aluminum contents (x < 0.38) whereas for a high Al-content, above x=0.70, a single-phase hexagonal structure is obtained. For intermediate Al-contents, a two-phase structure is formed. The cubic structured films exhibit higher hardness than the hexagonal structured ones. A low bias results in N-rich films with a partly defect-rich microstructure while a higher substrate bias decreases the grain size and increases the residual stress in the cubic ZrAlN films. Recrystallization and out-diffusion of nitrogen from the lattice in the cubic ZrAlN films takes place during annealing at 800 ◦C, which results in an increased hardness. The cubic ZrAlN phase is stable to annealing temperatures of 1000 ◦C while annealing at higher temperature results in nucleation and growth of hexagonal AlN. In the high Al-content ZrAlN films, formation of ZrN- and AlN-rich domains within the hexagonal lattice during annealing at 1000 ◦C improves the mechanical properties.
Place, publisher, year, edition, pages
American Vacuum Society , 2012. Vol. 30, no 3, 031504- p.
National CategoryNatural Sciences
IdentifiersURN: urn:nbn:se:liu:diva-75172DOI: 10.1116/1.3698592ISI: 000303602800015OAI: oai:DiVA.org:liu-75172DiVA: diva2:504297
funding agencies|VINN Excellence Center on Functional Nanoscale Materials (FunMat)||2012-02-202012-02-202015-06-01Bibliographically approved