I am currently doing some fabrication work on microfluidic system. The
sytem requires a glass cover with some reservoir opens (Diameter=3mm),
as well as some vias (Diameter from 10microns to 50 microns). For
those through holes, what is the suggested method to fabricate? Laser
drilling, HF etching, or DRIE? any others? which will be the simplest,
and achieve the best results?

Thanks a lot in advance!
Steven