Hi everyone,

I am trying to infiltrate PMMA into deep and narrow (sub-micron) grooves
etched into silicon. I have tried pouring a 0.1% solution of PMMA in
chloroform on top and just letting evaporate the solvent. But the
Polymer did not want to go into the gap and the result was a groove
filled with air and covered by a thin PMMA "roof". I was thinking about
using an adhesion promoter (HMDS?) to make the sidewalls of the groove
more hydrophobic s.t. the solution is "sucked" into the gap by capillary
forces. However I do not know how to make sure that the adhesion
promoter penetrates the gap in the first place.

Does anyone have experience with infiltrating polymers into
Si-structures? Which adhesion promoter could I try? Any idea if changing
the solvent could help? Any comment is welcome!

Thank you

Christian

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Christian Koos

Institut für Hochfrequenztechnik und Quantenelektronik (IHQ)
University of Karlsruhe
Karlsruhe, Germany