Effect of aluminum contents on sputter deposited CrAIN thin films

摘要

Pure CrN and CrAIN films with varied Al concentrations were prepared onto Si(100) substrates by an unbalanced reactive dc-magnetron sputtering system. The crystal structure, chemical states, and microstructure of the films were characterized by X-ray diffraction, X-ray photoelectron microscopy, transmission electron microscopy whereas mechanical properties were determined by nano-indentation measurements. XRD results showed a prominent (200) reflection in both CrN and CrAIN films. Results demonstrate that CrAIN films formed a solid solution and doping of Al atoms replace the Cr atoms affecting the lattice parameter and crystallization of the films. All Al doped films were of B1 NaCl-type structure, demonstrating that CrAIN films primarily crystallized in cubic structure. Microstructural investigation by TEM for a CrAIN film containing Al content of 24.1 at.%, revealed that there exists an amorphous/nanocrystalline domains (grains of about ~ 11 nm) and hardness increases 22% when compared with pure CrN film.