Microcontact printing and pattern transfer with a tri-layer processing

We describe a new approach of microcontact printing which is based on a tri -layer processing. The replication process has four steps: (1) preparation of gold-PMMA-substrate by sputtering and spin-coating deposition; (2) patte rn transfer with alkanethiol molecules from a PDMS stamp to gold; (3) wet e tching of gold and (4) reactive ion etching of under-layer PMMA. By this me thod, we succeeded in fabricating microstructures in PMMA resist which are suitable for further hard material pattern transfers, thereby providing an enhanced process compatibility with most of microfabrication steps.