This paper investigates the effect of O2 plasma treatment on the electric property of Cu/SiCOH low dielectric constant (low-k) film integrated structure. The results show that the leakage current of Cu/SiCOH low-k integrated structure can be reduced obviously at the expense of a slight increase in dielectric constant k of SiCOH films. By the Fourier transform infrared (FTIR) analysis on the bonding configurations of SiCOH films treated by O2 plasma, it is found that the decrease of leakage current is related to the increase of Si-O cages originating from the linkage of Si dangling bonjs through O, which makes the open pores sealed and reduces the diffusion of Cu to pores.