Original Paper(Vol.62 No.10 pp.634-639)

Self-Crack-Healing Behavior of SiNx/SiCy Nano-Laminated Thin Film under High Temperature Environment

Masanori NAKATANI, Junki NISHIMURA, Satoshi HANAKI and Hitoshi UCHIDA

Abstract:A self-crack-healing behavior of SiNx/SiCynano-laminated thin film under high temperature environment was investigated. The films were fabricated on silicon substrate by an ion beam assisted deposition. The thickness of the SiNx/SiCy nano-laminated film was 1ƒÊm and four layered film was deposited. To compare with the crack healing behavior of laminated film, SiNx and SiCy monolayer films were also fabricated. After the deposition, the pre-cracked samples were heated using an electric furnace in an air atmosphere at the temperature of 600 Ž to 1200 Ž. In the case of SiNx and SiCy monolayer films, the crack was poorly healed after heating at the temperature lower than 800Ž. This was because the size of a crack opening increased after heating due to the release of residual stress. On the other hand, slight crack healing occurred for 24 h at the temperature of 600Ž. It was confirmed that Auger electron count for oxygen atom was high along the healed crack, indicating that the crack healing was achieved by oxidation reaction on crack plane. Crack healing improved with an increase in the heating temperature and time. Moreover, the crack healing finished for 72 and 24 h at 600 and 800Ž, respectively. From these results, we concluded that SiNx/SiCy nano-laminated film has a superior self-crack-healing ability. However, the heating over 1200 Ž caused oxidation of film overall and disappeared the laminate structure. From these results, it is suggested that an upper limitation of heating temperature exists for self-crack-healing of SiNx/SiCy nano-laminated thin film.

Key Words:Self-healing, Crack, Laminated thin film, High temperature, Silicon nitride, Silicon carbide