Dry release of all-polymer structures

We present a simple dry release technique which uses a thin fluorocarbon film for efficient removal of plastic microdevices from a mould or a handling substrate by reducing the adhesion between the two. This fluorocarbon film is deposited on the substrate in an advanced Si dry etch device utilising the C4F8 passivation plasma. Micromachined polymer chips made of SU-8 are removed from the handling substrate by lifting them off using mechanical tweezers. Effective release of chips of several mm2 size within a few seconds and the lift-off of fragile, 5.5-μm-thin cantilevers at a yield of almost 100% were demonstrated on wafer-scale. The fluorocarbon film showed excellent compatibility with metal etch processes and polymer baking and curing steps. It further facilitates demoulding of polydimethylsiloxane stamps suitable for soft-lithography.