Thanks a bunch for the response. I do have negative slope. When I tried to
make just the array structure on the wafer, I exposed it by 10, 20 under and
10,20,30,40,50 percent over the recommended values. All them peeled out,
when I cast the PDMS. Also, I observed the there is negative slope like
Gareth mentioned.

If i try to spin the second layer, I dont see any alignment markers to align
the second layer. Is there any way of achieving this. Right now, when I do
PEB, I see the alignment marker from the first layer and then align it to
the second.

Cheers,
Vishwa