Monte Carlo simulation and experimental study of an electron cyclotron resonance plasma for thin film deposition

Abstract

Summary form only given, as follows. The interest in generating plasma by electron cyclotron resonance (ECR) interaction arises from the favorable features in its electron energy distribution (EED). ECR plasma has been shown to be particularly suitable for the synthesis of hard diamond-like carbon (DLC) films. This is because the ECR plasma has a low background gas pressure (10/sup -5/ to 10/sup -2/ torr at 298/spl deg/ K) but high ionization percentage (/spl sim/10%) and a large electron energy (up to 10 eV). Its EED consists of two temperature components, and the temperature of the tail portion of electrons can exceed 30 eV. The ECR plasma is also being considered for the deposition of polycrystalline diamond films, however the success has been limited. Monte Carlo simulation of electron behavior in an ECR microwave discharge maintained by the TM/sub 11/ mode fields of a cylindrical waveguide has been performed. The results show that at low pressure (/spl sim/0.5 mtorr) the temperature of the tail portion of the EED exceeds 40 eV, and the sheath potential is about -200 V. These results are about twice as high as the previous results using TM/sub 01/ mode fields. The produced ECR plasma is aimed at assisting the growth of polycrystalline diamond films and DLC films. An ECR plasma source has been designed accordingly. A Langmuir probe is used to measure the characteristics of the plasma. Hydrogen mixed with 1% methane at a pressure of 67.5 mPa (/spl sim/0.5 mtorr) is used as the background gas.