Hi Edouard, Thank you very much for your interest on my question. I did not start this experiment work. I also want to know which type of polymer substrate is suitable. It is possible to write sub 100 nm pattern on PET or PS sheet by EBL. But I don't know whether it can be etched uniformly (like Si) by RIE. If it works, we can get flexible organic master mold. Meng Gang Hi Prasanna, Thanks for your reply. As you said, microfabrication or nanofabrication is strongly dependent on the material. I want to make ordered nanohole (diameter: ~100nm, depth ~100nm) pattern on solid substrate. By using it, we can get PDMS replica stamp for soft lithography. Si(001) was widely used as master mold. One disadvantage is that fine PDMS will stick to it even using anti-stick layer. PDMS may be compatible with organic material. So if we can produce nanopattern on organic substrate, it may be beneficial to soft lithography. Meng Gang