In Situ Analysis of Incident Ions on Chamber Surface in Electron Cyclotron Resonance Etching

Abstract

Incident ions on the chamber surface in electron cyclotron resonance plasma were characterized in situ using a quadrupole mass analyzer, which was shielded with an 1-mm-thick cylinder made of highly permeable material. The incident ions were identified as Cl_x⁺, BCl_x⁺, Al_xCl_y⁺, C_xCl_y⁺ and Si_xCl_y⁺. Their incident energy was about 5 eV, as determined by the potential difference at the sheath. The BCl_x⁺ incident ions reacted with OH which is abundant on the surface of the quartz cylinder and formed B₂O₃ as identified by infrared reflection absorption spectroscopy.