Plasma Treatment and Plasma Polymerization by Self-Oscillating 2-MHz Generator

Abstract

A 2-MHz generator was used for plasma treatment and plasma polymerization and compared with 13.56-MHz plasma. Without a matching unit, the 2-MHz generator can match the impedance by adjusting its frequency to create stable plasma, which is called "self-oscillation". Unlike the ordinary rf generator, as another advantage, the 2-MHz generator showed little radio-wave interference. In the O₂ plasma treatment of HDPE and PP plates, the surfaces became hydrophilic for both the frequencies, in which 2 MHz showed superior treatment effect to 13.56 MHz. In the plasma polymerization of CHF₃ and C₂H₄, the deposition rate in 2-MHz plasma was lower than that in 13.56 MHz. However, the properties of the deposited films were alike.