You can etch soda-lime glass with HF or BOE. The etch rate will be well
under 1 um/min. Photoresist will tend to lift if used as a mask. I have
used Cr a mask for etching Pyrex with BOE. However this resulted in
undercut greater than the etch depth. I read somewhere that Cr with an
over layer of Au works better than Cr by itself. I've also heard of
people using polysilicon as a mask. You can etch soda-lime glass with
SF6 plasma, but the etched surface tends to be very rough.
Roger Shile