| AVS 64th International Symposium & Exhibition | |
| Plasma Science and Technology Division | Tuesday Sessions |
| Session PS-TuP |
| Session: | Plasma Science and Technology Poster Session |
| Presenter: | Hsin-Chang Chang, National Tsing Hua University, Taiwan, Republic of China |
| Authors: | H.C. Chang, National Tsing Hua University, Taiwan, Republic of China C.Y. Chen, National Tsing Hua University, Taiwan, Republic of China P.S. Luo, National Tsing Hua University, Taiwan, Republic of China K.C. Leou, National Tsing Hua University, Taiwan, Republic of China |
| Correspondent: | Click to Email |
Radio frequency capacitively coupled plasmas (CCPs) are important plasma reactors for applications in a wide range of areas such as thin film deposition and dry etching, etc. The property of the discharge, e.g., plasma density and uniformity, can be tailored or enhanced by integrating the hollow cathode effect. In this study, fluid model numerical simulation is employed to investigate the effect of slots or holes on the grounded electrode, instead of the powered electrode as in conventional hollow cathode enhanced CCPs, on the discharge characteristics. Two different CCP reactors are investigated. The first one is an indirect Ar/H2 CCP where a grounded mesh is placed between the two electrodes of a conventional CCP. The effect of the side of the holes on the plasma behavior, as well as the dependence of the ratio of ion to neutral radicals fluxes are analyzed. Simulation Results show that, as a result of the grounded mesh/grid that separating the two chambers, the flux of both ionic and reactive neutral species drop significantly, by a factor of ~1/1000 - 1/10000, from the top main chamber to the bottom drift chamber. This, in term, implies that the ion energy flux incident on the grounded bottom electrode should be minimal, and thus damage to the substrate surface due to ion bombardment can be significantly reduced. Moreover, simulation results show that hole size less than sheath thickness is needed for low ion flux toward substrate and low plasma potential in the bottom chamber. The second reactor we investigated is a CCP with a slot on the top grounded electrode while the bottom one is powered by rf voltage. Simulations are carried out for two different feed gases, Ar and CF4. Results from parametric studies and comparisons of hollow cathode effect between electropositive and electronegative discharges will be presented.
Acknowledgement
Work supported by the Ministry of Science and Technology, ROC (Taiwan).