組成変調したTi-TiN多層薄膜における高強度化機構 Hardening Mechanism of Compositionally Modulated Ti-TiN Multilayer Films
Crystal structure, dynamic hardness and internal stress of compositionally modulated Ti-TiN multilayer films were examined in order to discuss the mechanism of hardness enhancement by compositional modulation. The hardness of the films showed a sharp peak at10 nm and was larger than that of a monolithic TiN film. XRD patterns of the films with short modulation periods showed peaks assigned to TiN single phase. With increasing the modulation period to 20 nm, XRD peaks assigned to TiN phase were broadened and weakened. Further increasing the period, broad peaks assigned to Ti were emerged. Compressive stress, which causes the films hardened, was observed in monolithic Ti and TiN, and compositionally modulated Ti-TiN films. Energy dissipated ratio defined as the ratio of dissipated energy to applied energy showed the minimum at the modulation period of 10 nm, indicating that plastic component of the deformation energy decreased. Reduction of the plastic component at the modulation period of 10 nm was in good agreement with results obtained by the hardness measurement. Decreasing of the plastic component strongly suggests that TiN layers, which has a high elastic modulus, plays an important part in the plastic deformation of the films at short modulation period.
真空 42(7), 657-662, 1999-07-20
The Vacuum Society of Japan