NEMS by Sidewall Transfer Lithography

A batch fabrication process for nanoelectromechanical systems (NEMS) based on sidewall transfer lithography (STL) is demonstrated. The STL is used to form nanoscale flexible silicon suspensions entirely by conventional photolithography. A two-step process for combining microscale and nanoscale features is used to fabricate double-ended and single-ended electrothermal actuators with a minimum feature width of 100 nm and an aspect ratio of 40:1. All devices are fabricated by deep reactive ion etching in 4.5-μm-thick silicon using bonded silicon-on-insulator material. The process could allow low cost fabrication of nanoscale sensors and actuators.