Nanoindentation Techniques for the Evaluation of Silicon Nitride Thin Films

• Main Author: Mangin, Weston T
• Format: Others
• Published: DigitalCommons@CalPoly 2016
• Subjects: Nanoindentation; Nanoimpact; Nanoscratch; Silicon Nitride; Biomaterials; Ceramic Materials
• Online Access: https://digitalcommons.calpoly.edu/theses/1690; https://digitalcommons.calpoly.edu/cgi/viewcontent.cgi?article=2899&context=theses

Silicon nitride thin films are of interest in the biomedical engineering field due to their biocompatibility and favorable tribological properties. Evaluation and understanding of the properties of these films under diverse loading and failure conditions is a necessary prerequisite to their use in biomedical devices. Three wafers of silicon nitride-coated silicon were obtained from Lawrence Livermore National Laboratory and used to create 96 samples. Samples were subjected to nanoindentation testing to evaluate the mechanical properties of the film. Samples were subjected to nanoimpact testing to compare the damage resistance of the film to separate nanoimpact types. Samples were subjected to nanoscratch testing to evaluate the consistency of the critical load of the film. Results showed that there were no significant differences in the mechanical properties of the film across the tested groups. There was a significant difference observed in the rate of damage to the film between pendulum oscillation nanoimpact testing and sample oscillation nanoimpact testing, with the former causing more damage with all experiment variables controlled for. Results showed that the critical load measure for the film was significantly different between different nanoscratch test parameters. The conclusions from this study will support future work for in vitro and in vivo testing of ceramic thin films for biomedical applications.