Re: nitride dry etching


vijay.rawat@xxxxxxxxx wrote:
> I have a 400 nm thick TiN/GaN multilayer film on a Al2O3 substrate and
> i want to do a cross-plane electrical measurement of this film for
> which i have to make a back contact to the bottom TiN layer (since the
> substrate is insulating). Any ideas?
> I was planning to dry etch the multilayer from top using either laser
> etching, reactive ion etching or FIB, but all of them have
> complications. All ideas/opinions are welcome?
>

Ion gun etch in ultrahigh vacuum. Not sure how you'd know where you
are in the cross-section without removing from vacuum and doing
ellipsometry or something like that. You should consider doing the
electrical measurements in ultrahigh vacuum as well, as I think the TiN
will at least partially revert back to the oxide in the presence of
oxygen.

.