Nanomechanical structures with 91 MHz resonance frequency fabricated by local deposition and dry etching

We report an all-dry, two-step, surface nanoengineering method to fabricate nanomechanical elements without photolithography. It is based on the local deposition through a nanostencil of a well-defined aluminum pattern onto a silicon/silicon-nitride substrate, followed by plasma etching to release the structures. The suspended 100-nm-wide, 2-mum-long, and 300-nm-thick nanolevers and nanobridges have natural resonance frequencies of 50 and 91 MHz, respectively. The fabrication method is scalable to a full wafer and allows for a variety of materials to be structured on arbitrary surfaces, thus opening new types of nanoscale mechanical systems.