Dear colleagues:
Can anyone let me know what you are using to measure the thickness of two
layers of photoresist? The bottom layer is around 30 nm and the top layer is
around 1um. the substrate may be silicon or silicon dioxide. Now I am using
NanoSpec, but was told to be careful with the data, so I want to check with
other equipment.

Another question is that when I develope the top layer photoresist, how to
make sure all exposure area are totally removed? so that the bottom layer can
be pattern. On the other hand, if i can get pattern on the top layer, is it
enough to say that the developer of the top layer is safe to the bottom
photoresist?

Thanks.

Regards,
Yilei