Nanomechanical characterization of sputtered RuO2 thin film on silicon substrate for solid state electronic devices

This paper presents the study on characterizing the mechanical and interfacial properties of ruthenium dioxide (RuO2) film on silicon substrate using nanoindentation tests. RuO2 film is deposited by DC reactive magnetron sputtering; the structure and morphology of the film are characterized using X-ray diffraction and scanning electron microscopy, and elastic modulus and hardness are determined by nanoindentation with a standard Berkovich indenter and found to be 232.74 ± 22.03 GPa and 20.43 ± 2.37 GPa, respectively. In addition, the interfacial adhesion properties of RuO2 film on Si substrate are studied. Spontaneous interfacial delamination is induced by indentations with wedge (90° and 120°) and conical indenter tips. The relationship between the indentation load-displacement (P-h) curves and the interfacial crack initiation and propagation are analyzed by combining FIB sectioning and SEM imaging. Through this analysis, the interface toughness of as-deposited RuO2 film is found to be 0.046 ± 0.003 J/m2 for 90° wedge indentation, 0.050 ± 0.004 J/m2 for 120° wedge indentation, and 0.051 ± 0.003 J/m2 for conical indentation.