Ashing properties in a surface-wave mode plasma with a high-permittivity alumina window

Ashing properties in a surface-wave mode at 133 Pa and 1 kW with an alumina disk-plate window are investigated by comparison of those in a volume mode with a quartz disk-plate window. In the surface-wave mode, plasma is confi ned to tile alumina window surface area and ashing in a downstream area is carried out mainly by atomic oxygen. The ashing activation energy of 0.42 e V in the surface-wave mode ashing is comparable to 0.5 eV with an ashing co ndition by atomic oxygen at the ground state [O(P-3)](the so-called downstr eam state). These results indicate that the plasma in the surface-wave mode can realize a downstream ashing condition. On the other hand, ashing with a quartz window was done by plasma, where the activation energy is influenc ed by built-in high-frequency magnetic field. Moreover, the ashing rate dis tribution in the Surface-wave mode characterized with the alumina window is more uniform than that in the volume mode with the quartz window.