Piezoresistivity Characterization of Synthetic Silicon Nanowires Using a MEMS Device

This paper presents a microelectromechanical systems (MEMS) device for simultaneous electrical and mechanical characterization of individual nanowires. The device consists of an electrostatic actuator and two capacitive sensors, capable of acquiring all measurement data (force and displacement) electronically without relying on electron microscopy imaging. This capability avoids the effect of electron beam (e-beam) irradiation during nanomaterial testing. The bulk-microfabricated devices perform electrical characterization at different mechanical strain levels. To integrate individual nanowires to the MEMS device for testing, a nanomanipulation procedure is developed to transfer individual nanowires from their growth substrate to the device inside a scanning electron microscope. Silicon nanowires are characterized using the MEMS device for their piezoresistive as well as mechanical properties. It is also experimentally verified that e-beam irradiation can significantly alter the characterization results and must be avoided during testing.