NEMS by multilayer sidewall transfer lithography

This paper reports an extension of a recently demonstrated technique to fabricate nano-electro-mechanical systems (NEMS) using sidewall transfer lithography (STL). The process uses three pattern transfer steps. Each step only requires optical lithography, making the method suitable for low-cost, wafer scale fabrication. The first two involve STL and are used to form nanoscale features such as suspension beams. These may now intersect, breaking an important restriction of single-layer STL NEMS. The third involves conventional lithography and is used to form microscale features such as anchors. Current nanoscale features have a width of 100 nm and an aspect ratio of 50 : 1. The new process should allow mass parallel fabrication of complex NEMS.