This should not be a problem. We've do this sometimes as well (with p-type
wafers), often with somewhat thicker nitride. Only difference that we've
seen is that you often need a somewhat higher bond-voltage and/or a longer
bondtime, but I don't think this should be a problem in your case.
Good luck.

Jason

___________________________________________________________
Jason Viotty
Senior Process Engineer
C2V
http://www.c2v.nl