The PIC/MCC Simulation Of Electron Cyclotron Resonance Discharge

Electron cyclotron resonance (ECR) microwave discharge plasma devices have received a great deal of attention as sources for micro-electronic fabrications, accelerators, atomic physics experiments, and industrial applications et al, due to their high reactive species density, high degree of ionization, low neutral pressure, big volume, uniform, electrodeless operation, and controllable. And the theoretical and computational simulation has been the important method to investigate the characteristics of ECR discharge or ECR plasma.A theoretical and computational model has been presented to study the ionization of the ECR discharge using a quasi-three-dimensional electromagnetic particle-in-cell plus Monte Carlo collision (PIC/MCC) method. The major achievements are listed as the following:(1)Particle, fluid, and hybrid models are focused on the theoretical and computer simulation of the ECR discharge and ECR plasma. In this paper, these three models are reviewed, summarized, and contrasted respectively. It is important to study the ionization of the ECR discharge. And the PIC/MCC method in particle model is preponderant in the simulation of the ECR discharge and ECR plasma.(2)A theoretical model has been proposed to study the ionized characteristics of the argon ECR discharge. The propagation of self-consistent microwave, plasma collective motion, collisions between particles, the interaction between the charged particles and the boundary are taken into account. Elastic, excitational, and ionizing electron-neutral collisions and elastic, charge exchange ion-neutral collisions are included. The cross sections are the functions of particle's energy. And the secondary electron emission model has been summarized and developed to simulate the behavior of the electron which comes to the boundary in the gas discharge. The secondary emission coefficient is dependent on the impact energy and angle of incidence of the primaries, as well as the material properties of the target. (3)A quasi-three-dimensional electromagnetic PIC/MCC method is used. The simulation code is the original work. The Finite-Difference Time-Domain (FDTD) method plus the source of total/scattering field system and the absorbing boundary condition are used to calculate the propagation of microwave. The interaction between the charged particles and microwave fields are described by particle-in-cell method. The collision processes and the behavior of charged particle which reach the boundary are treated with Monte Carlo method. And the advantages both PIC method to plasma collective and MCC method to collisions are obtained.(4)The detailed microscopic information about the distributions of charged particles and electromagnetic fields from the initial stage to the steady state of ECR discharge are obtained, and the spatio-temporal evolution of the movements of charged particles and the propagation of microwave are shown. The macroscopic features of ECR discharge and ECR plasma are also found by the statistical treatment of the above microscopic information. The effects of neutral pressure, the profiles of external static magnetic and microwave power on the characteristics of the ECR discharge and ECR plasma are investigated to make optimization of the ECR plasma.