Texture and microstructure of Cr2O3 and (Cr,Al)2O3 thin films deposited by reactive inductively coupled plasma magnetron sputtering

Cr₂O₃ and (Cr,Al)₂O₃ films were grown using reactive dc and inductively coupled plasma magnetron sputtering at substrate temperatures of 300-450 °C. For pure chromia, α-Cr₂O₃ films with fiber texture were grown; the out-of-plane texture could be controlled from < 0001> to < 101?4>. The former texture was obtained as a consequence of competitive growth with no applied bias or inductively coupled plasma, while the latter was obtained at moderate bias (− 50 V), probably due to recrystallization driven by ion-bombardment-induced strain. By reactive codeposition of Cr and Al, a corundum-structured metastable solid solution α-(Cr,Al)₂O₃ with Cr/Al ratios of 2-10 was grown with a dense, fine-grained morphology. Hardness and reduced elastic modulus values were in the ranges 24-27 GPa and 190-230 GPa, respectively.