Hello,
I'm trying to etch by RIE very deep pillars (16 um) in a GaAs/AlGaAs
superlattice (30% Al content) with SiCl4/Cl2/Ar sources.
The result is often not very good since sometimes I have filaments with
a resulting rough surface. I've been told that one problem could be an
excess of Cl in the mixture but its reduction did not lead always to
better results.
Do you have some ideas?
Is it maybe a kind of contamination or leak in the chamber?
Thank you

Lorenzo