Hi,

I have a question about getting rid of a borosilica film on bare
silicon.  We are using a commercially available spin-on dopant
(Emulsitone, Borosilica film 5e20) on bare silicon, after which the
wafer goes through a rapid thermal anneal step.

But now we can't seem to get rid of all of the borosilica film to
continue processing.  Using BOE, we managed to get most of it off, but
suddenly we have reached a point where the film seems virtually
unaffected by the HF.  We're trying to keep this as a wet etch to
minimize damage to our device.

Any suggestions as to why we're having this problem, a better etch
method/formulation, or other experiences with this would be appreciated.

Thanks!