Adhesion and fracture of tantalum nitride films

Indentation fracture and continuous nanoscratch testing were used in this study to determine the effects of compressive residual stresses on the fracture of thin sputter-deposited tantalum nitride films. Some films were tested in the as-deposited condition while others were vacuum annealed at 300 degrees C. The only discernible change in structure was a surface rearrangement of atoms into parallel arrays of striations on the vacuum annealed samples revealing a high compressive residual stress state after deposition. Comparison of results and application of mechanics-based models showed that these stresses had a strong effect on the fracture of the as-deposited films. The models also provided a good measure of the residual stress levels and interfacial strain energy release rates. (C) 1998 Acta Metallurgica Inc.