Stress-induced surface damages in Ti–Si–N films grown by magnetron sputtering

Abstract

The compressive-stress-induced surface damages in the Ti 1 − x − y Si x N y films (0≤ x ≤0.12) deposited on Si(100) substrates by magnetron sputtering were examined by scanning electron microscopy. It was found that the degree of surface damage in the Ti 1 − x − y Si x N y films depended on the Si concentration. For the films with relatively high Si contents, e.g. Ti 0.32Si 0.12N 0.56 and Ti 0.38Si 0.08N 0.54, no significant surface failure could be observed. However, when the Si concentration was low, e.g. Ti 0.39Si 0.04N 0.57 and Ti 0.44N 0.56, the presence of higher compressive stresses in the films induced large-area surface damages. Further examination revealed that spalling was the dominant stress relief mode in the Ti 0.44N 0.56 film, whereas both spalling and buckling were found in the Ti 0.39Si 0.04N 0.57 film. In particular, most of the buckling patterns (e.g. circular bubbles or varicose patterns, straight-sided wrinkles, and telephone cords) in the Ti 0.39Si 0.04N 0.57 film were with cracks at the midpoints of the delaminated regions. The correlation between the observed Si-content-dependent phenomenon and the film microstructure was addressed. The origins of the buckling patterns with cracks were also discussed.