Hi,

You didn't really give a lot of details of your process, so it is difficult to
diagnose specifically.  If you are using a hot plate for baking the resist,
glass takes much longer to heat up than GaAs, so you may not be baking it long
enough.  You should be using an adhesion promoter, so if not, this could also be
a cause of failure.  Since you can do standard positive lithography, it may
depend on your pattern.  Finally, image reversal usually requires a longer
image-wise exposure (with the mask) than positive to make sure that you expose
at the resist/substrate interface.

Brad
_________________________________

Brad Cantos
brad.cantos@holage.com
http://holage.com




On 10 Dec 2011, at 2:40 PM, Selda Sonusen wrote:

> Hello All,
>
> I am trying to  do image reversal process on transparent substrate (microscope
lamel). I am using recipe which works for SiO2 and GaAs,But when I develop lamel
and put it on DI water all resist go away for image reversal,But I can do
positive lithography on again microscope lamel. I can achieve mask pattern.  Do
you have any idea?  Thanks