Stress-assistant selective etching mechanism for lithography-independent nanofabrication

We report a novel stress-assistant selective etching (SASE) mechanism for nanofabrication, which is discovered that tensile stress can increase dry-etching rate. By introducing patterned stress, this mechanism can realize selective etching, and be used to achieve nanostructures independent of lithography. Based on the mechanism, we employ focused ion beam (FIB) to introduce stress while milling, and successfully fabricate a sub-100 nm nano-pore and a shuttle-shaped structure with 10 nm nano-cantilevers on a 96.9 nm-thick crystal-silicon film without restrictions of lithography as well as the precision of FIB-processing. Using the SASE mechanism with stress distribution patterns, we are possible to acquire desired nanostructures.