Thanks for the suggestions. I think I have not made myself quite clear. I am not releasing Su-8 structures, I am transferring the metal structures on Si to Su-8.( For example I have wires made of Cr/ Ag or Cr/ Au sitting on Si wafer. Then i have an layer of Su-8 on top of the structures. So the metal structures are sandwiched between Su-8 on one end and Si on the other, the idea is to have the wires transferred on Su-8 layer). I had tried different methods for releasing the structures,like having a Ti or Cr layer covering the entire wafer and then try to etch away Cr or Ti,but the etchant couldn't go all the way to the middle of the wires might be because of surface tension. So I had to resort to etching the whole wafer. Cheers A