Hi,

I'm using XeF2 to etch a Si wafer that has different feature sizes (squares)
on the same surface, like 1mm, 0.3mm, 0.1mm etc. I found that the etch rate
decreases as the feature size decreases. I used 3 torr of XeF2 for 30 sec
and various cycle numbers. I wonder if this is common with XeF2 etching or
has something to do with the patter of the gas inlet holes over the wafer
surface. Please advise if there are any ways to obtain uniform etch rate on
different feature sizes on the same wafer surface using XeF2.

Thanks,

--
Junjun Wu
Twin Creeks Technologies
Phone: 408-759-1426
Fax: 408-986-9142