Numerical investigation on plasma and poly-Si etching uniformity control over a large area in a resonant inductively coupled plasma source

In high-density plasma etching processes for ultra-large-scale integrated (ULSI) circuits, the uniformity of the plasma over a large area is of major concern. Recently a resonant inductively coupled plasma source [S. S. Kim et al., Appl. Phys. Lett. 77, 492 (2000)] has been proposed for large-area plasma processing, which achieves large-area plasma uniformity by properly tuning its antenna with an external variable capacitor. In the present paper, the plasma transport and poly-Si etching characteristics of this plasma source have been numerically investigated using a self-consistent model for electron heating, plasma transport, and microscopic etching profiles. The numerical simulation results indicate that uniform poly-Si etching over 300 mm in diameter can be easily achieved in this plasma source.