Dear All,

I am building some microfludic structure on SU-8 and use DRIE as the last step
to etch through the wafer. However, after the DRIE etch, there leaves a very
thin layer of teflon-like particles that not only changes the surface wetting
properties but also acts as an insulating layer. This insulating layer
prevents fluids from coming into contact with the electrodes in my device,
thus "disabling" the working of the device. I was told a piranha etch can
remove that layer, but the problem is that it attacks SU-8 as well. Anyone has
better ideas for the removal of this layer? Thanks very much!

Gavin