Precise voltage contrast image assisted positioning for in situ electron beam nanolithography for nanodevice fabrication with suspended nanowire structures

摘要

In this paper, we demonstrate precise voltage contrast image positioning for in situ electron beam (e-beam) nanolithography to integrate nanowires into suspended structures for nanoswitch fabrication. The positioning of the deflection electrodes on the nanowires can be well controlled using a precise voltage contrast image positioning technique, where the error can be minimized to about 10 nm. Using such a method, dispersed nanowires can be sandwiched between two layers of resist and suspended by one e-beam nanolithography process without any etching. The in situ e-beam nanolithography eliminates the stage movement error by preventing any movements of the stage during the nanolithography process; hence, a high precision laser stage and alignment marks on the substrate are not needed, which simplifies the traditional e-beam nanolithography process. The nanoswitches fabricated using this method show ON and OFF states with the changes of applied voltages. This simplified process provides an easy, low cost and less time-consuming route to integrating suspended nanowire based structures using a converted field emission scanning electron microscope e-beam system, which can also be customized to fabricate multi-layer structures and a site-specific nanodevice fabrication.