Fabrication of quasi-three-dimensional micro/nanomechanical components using electron beam cross-linked poly (methyl methacrylate) resist

We present a useful, flexible, and simple surface nanomachining technique which employs electron beam cross-linked poly (methyl methacrylate) (PMMA) as a high-resolution negative resist for the sacrificial layer. This technique simplifies the fabrication of quasi-three-dimensional micro/nanomechanical components without the need to pile up two-dimensional layers. The high compliance of cross-linked PMMA allows the stress relaxation of the mechanical structures to begin after the deposition of each mechanical layer. This happens prior to the stiction-free dry release step. The fact that it can be used both as an insulating layer and sacrificial layer allows the high-resolution patterning of micro/nanomechanical structures alongside unique multilayer devices. We demonstrate this technique by the characterization of PMMA as a function of electron irradiation levels and by referring to fabricated micro/nanoelectromechanical structures and devices.