Crack-healing behavior induced by oxidation in SiN/SiC nanolaminated films

The crack-healing behavior of SiN/SiC nanolaminated thin films in a high-temperature environment was investigated. Laminated films with a thickness of 1 μm were fabricated on a silicon substrate by ion-beam-assisted deposition. The number of layers was fixed to four, and the bilayer ratio of SiN to SiC was set to either 1 or 3. Cracked samples were heated in an air atmosphere at 600-1200 °C. In the case of the SiN/SiC nanolaminated film, the crack was perfectly filled with the oxide by heating at 1000 °C, whereas the crack of the SiN film was not healed. Moreover, the filled crack length of the SiN/SiC laminated film with a bilayer ratio of 1 was longer than that of the same type of film with a bilayer ratio of 3. These results suggest that inserting SiC layers in SiN films may confer crack-healing ability to SiN thin films. Moreover, the influence of heating on crack‐healing was investigated systematically. Crack‐healing was improved with increasing heating temperature and time.