Dear all

I'm trying to etch a Lithosil Q1 silica wafer with an Alcatel 601E ICP
etching machine and a 2 um aluminum mask.
The machine works with a LF-generator at 38 kHz and has a ceramic
wafer-clamping.

As a result I get a very slow etching-rate of about 20 nm/min.
Now I'm wondering, if someone has similar experience or an explanation for
this phenomena.
Maybe, there are electrostatic charges at the aluminium-mask witch overlays
the electric field of the etcher etc.

Best regards

André