Stress Release Behaviors of Amorphous SiC/Si Structure during Annealing

Abstract

An amorphous SiC/Si crystal structure is annealed at 950°C for 30 min in hydrogen gas atmosphere. Shrinkage of the amorphous SiC film during the annealing results in stress at the SiC/Si interface. Release behaviors of the stress depend on both the thickness of the film and the orientation of the Si substrate. When the stress is more than the fracture limits of the film and the substrate, release of the stress results in breaks in the SiC/Si structure. On the other hand, when the stress is smaller than one of the two fracture limits, no break occurs. If the fracture limit of the film is smaller than that of the substrate, the breaks are straight lines and their direction depends on the orientation of the substrate. Moreover, if the fracture limit of the film is more than that of the substrate, the breaks become curved. Also, the density of the breaks, length per unit area on the substrate, depends on shrinkage of the film and orientation of the substrate. The effects of residual oxygen in the substrate are also discussed.