Fabrication of polynomial 3-D nanostructures in Si with a single-step process

This work demonstrated the ability to transfer a nanoscale 3-D polynomial structure of arbitrary shape into Si with a single step electron-beam lithography process. The technique involved employing a proximity correction algo- rithm, PYRAMID, to derive the dose distribution for a given 3-D structure by accounting for the electron scattering ef- fects of the surrounding pixels. The pattern was written into a polymethyl methacrylate (PMMA) resist and then succes- sively transferred into Si via reactive ion etching, where a 1:1 etching ratio between PMMA and Si was achieved. The pattern transferred into Si possessed nanoscale features and matched the desired pattern with high fidelity. C 2011 Society of Photo-Optical Instrumentation Engineers (SPIE). (DOI: 10.1117/1.3563601) Subject terms: 3-D nanolithography; single-step lithography; proxim- ity correction.