Improve the Charge Stability of SiO_2 Films by Plasma Treatment and Ion Implantation

摘要

The plasma surface treatment and ion implantation are utilized to improve the stability of charge storage of the SiO_2 film electret. The effects are obviously different when the different kinds of plasma are used, and when the ions with different energy and dose implanted into the SiO_2 film. To the plasma treatment, the best effect is obtained with argon plasma. After argon plasma treatment with the arcing at 700V and 15 minutes for the SiO_2 film electret, its charge storage has a similar stability as one after the chemical surface modification. To the ion implantation method, the remanent surface potential is 95% of primary one after ion implantation by Ar~+ with a energy of 150KeV and a dose of 2E11/cm~2. The experimental results show that argon plasma treatment and Ar~+ implantation change the hydrophilicity of the surface of SiO_2 film and prevent the electret charge from leaking, which is owning to the increase of the surface conductance by the vapor adherence on the surface. In addition, the plasma bombardment and ion implantation induce traps into the near-surface, which make the trapped charge stored stable.