Three-Dimensional Flow and Plasma Simulation for ICP Reactor with Different Injector Designs

To get a better uniformity of N% concentration on the wafer for an ICP reactor, two injector designs were proposed in this study, including baseline injector design and extend-length injector design. The current paper presents a systematic study on these two injector designs through comprehensive flow and plasma simulation.

Both injectors include center nozzle and side nozzle, which is a necessary configuration to control flow distribution and uniformity. Firstly, the effects of flow amount for center nozzle and side nozzle on flow distribution are investigated. For this simulation, the total N2 flow amount goes into center and side nozzle keep the same, while only the mass flow rate ratio changes. Results shows that, the baseline injector design demonstrates better velocity uniformity near the wafer. Secondly, the commercial software, CFD-ACE+, was used for plasma simulations of ICP reactor. Antenna design consists of inner and outer coils to control center/edge N% concentration for this ICP reactor. Plasma simulations were conducted for both injector designs under different inner and outer coils current ratio 1:2 and 1:3, respectively. Experiments are performed for baseline injector design and a good agreement was achieved, which means the plasma model used in this study is reasonable. Simulation results show that, the two injectors exhibit slightly different bulk plasma distributions. Baseline injector shows better plasma potential and plasma density uniformity near the wafer.