Dear Gavin,

HF: H2O  (1:100) should "work". I don't think it remove completly the
polymer-like left by DRIE, but it removes most of it. And I beleive that SU8
resists lite HF concentration.

Best regards,

Richard Beaudry
[email protected]

Gavin Wu gavinwu at engineering.ucsb.edu

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