SiO2-Iike film deposition on copper surface by diffuse discharge enhanced CVD has already achieved in our previous work.Recent attentions have been paid on the improvement of deposit efficiency of the SiO2-Iike film.In this paper,etching,the main competing process of depositing,and its influence on the deposit efficiency are investigated by analyzing the film thickness obtained under different discharge voltages and electrode structures (point-to-plate electrode and point-to-mesh electrode).