Interfacial fracture energy measurements in the Cu/Cr/polyimide system

The interfacial fracture energies, Γ, of the Cu/Cr/polyimide system were deduced under varying Cu film thickness and pretreatment conditions based on two methods: X-ray measurement by Park and Yu and theoretical methods by Moidu et al. The two methods showed reasonable agreement for most cases, imparting validity for both approaches. Estimated Γ values were quite independent of the metal film thickness and increased with the rf plasma power density of polyimide pretreatment as expected. Estimated values of Γ were 46.8±17.8, 170.3±42.9 and 253.9±44.4 J m−2 for the rf plasma power density of 0.03, 0.036 and 0.05 W cm−2, respectively.