サブミクロン銅薄膜の破壊じん性に及ぼす酸化の影響

抄録

To investigate the effects of oxide layer on fracture toughness of freestanding submicrometer-thick films, we conducted in situ field emission scanning electron microscopy (FESEM) fracture toughness tests in roughly 500-nm-thick Cu films with nanometer-thick oxide layer. In order to form oxide layer on specimen surface, heat treatment in dry air was conducted at 120°C-140°C. After the heat treatment, we removed oxide layer by argon ion sputtering method for some specimens. In all specimens, the notch root became blunt by applying a monotonic tensile load, and a crack was initiated from the blunted notch root. The critical crack tip opening displacement (CTOD) for crack initiation was evaluated on the basis of FESEM micrographs.