Local etch control for fabricating nanomechanical devices

We report on the fabrication of suspended nanoelectromechanical systems using an etch enhancement technique. Nanoscale beams are defined by conventional electron beam lithography, followed by locally enhanced etching via electron beam exposure. The structures are successfully suspended within the "etch-booster window" by using an HF vapor etch step. The method is simple, does not require a special setup, and allows the spatial and temporal fine-tuning of the underetching process.