| AVS 56th International Symposium & Exhibition | |
| Plasma Science and Technology | Thursday Sessions |
| Session PS2-ThM |
| Session: | Plasma Sources |
| Presenter: | Y. Yang, Iowa State University |
| Authors: | Y. Yang, Iowa State University M.J. Kushner, University of Michigan |
| Correspondent: | Click to Email |
Wafer diameters will soon transition from 300 mm to 450 mm at a time when excitation frequencies for capacitively coupled plasmas (CCPs) are increasing to 200 MHz or higher. Already for 300 mm tools, there is evidence that wave effects (i.e., propagation, constructive and destructive interference) affect the processing uniformity. The increase to 450 mm is likely to exacerbate these affects, perhaps requiring non-traditional tool designs. This is particularly important in dual frequency (DF) CCP tools in which there are potential interactions between frequencies. In this talk, we discuss results from a 2-dimensional modeling study of the plasma properties in 450 mm DF-CCP tools. To resolve wave and electrostatic effects, a full-wave Maxwell equation solver in the Hybrid Plasma Equipment Model is employed. To capture the high frequency heating, excitation rates are provided by spatially dependent electron energy distributions generated by a Monte Carlo simulation. A Monte Carlo simulation is also used to predict ion energy distributions as a function of radius on the substrate. Results will be discussed for plasma properties in DF-CCPs for low frequencies of ≤ 10 MHz and high frequencies up to 200 MHz, and gas pressures of < 10s mTorr. Segmented electrodes will be discussed as a means to suppress wave effects by making the electrical distance between the electrode feeds and the sheath edges as uniform as possible. The effects of tuning the lengths of the segments and the positions of rf feeds on plasma uniformity will be discussed.