Simulations of ECR processing systems sustained by azimuthal microwave TE(O,n) modes

Summary form only given. Low pressure (<5 mTorr) electron cyclotron resonance (ECR) sources are being developed for downstream etching and deposition, and production of radicals for surface treatment. The spatial coupling of microwave radiation to the plasma in these systems is a concern due to issues related to the uniformity of dissociation, electron heating, and ultimately process uniformity. To investigate these issues, we have developed a finite-difference-time-domain (FDTD) simulation for microwave injection and propagation. The FDTD simulation has been incorporated as a module in the 2-dimensional Hybrid Plasma Equipment Model (HPEM). Plasma dynamics are coupled to the electromagnetic fields through a tensor form of Ohm´s law. During each iteration through the model, the FDTD simulation uses a leap-frog scheme for time integration, with time steps that are 30% of the Courant limit, until reaching the steady state. Power deposition calculated in the FDTD module is then used in solving the electron energy equation. The system of interest uses circular TE(O,n) microwave mode fields injected along the axis of a cylindrically symmetric downstream reactor.