Fracture properties of hydrogenated amorphous silicon carbide thin films
- Resource Type
- Authors
- Reinhold H. Dauskardt; Yusuke Matsuda; Sean W. King; J. Bielefeld; J. Xu
- Source
- Acta Materialia. 60:682-691
- Subject
- Suboxide
Amorphous silicon
Materials science
Polymers and Plastics
Fracture (mineralogy)
Metals and Alloys
Fracture mechanics
Nanoindentation
Electronic, Optical and Magnetic Materials
Carbide
chemistry.chemical_compound
Carbon film
chemistry
Ceramics and Composites
Thin film
Composite material
- Language
- ISSN
- 1359-6454
The cohesive fracture properties of hydrogenated amorphous silicon carbide (a-SiC:H) thin films in moist environments are reported. Films with stoichiometric compositions (C/Si ≈ 1) exhibited a decreasing cohesive fracture energy with decreasing film density similar to other silica-based hybrid organic–inorganic films. However, lower density a-SiC:H films with non-stoichiometric compositions (C/Si ≈ 5) exhibited much higher cohesive fracture energy than the films with higher density stoichiometric compositions. One of the non-stoichiometric films exhibited fracture energy (∼9.5 J m −2 ) greater than that of dense silica glasses. The increased fracture energy was due to crack-tip plasticity, as demonstrated by significant pileup formation during nanoindentation and a fracture energy dependence on film thickness. The a-SiC:H films also exhibited a very low sensitivity to moisture-assisted cracking compared with other silica-based hybrid films. A new atomistic fracture model is presented to describe the observed moisture-assisted cracking in terms of the limited Si O Si suboxide bond formation that occurs in the films.