Tensile fracture of integrated single-crystal silicon nanowire using MEMS electrostatic testing device

Abstract

Tensile testing of single-crystal silicon (SCS) nanowire integrated into electrostatic micro electro mechanical system (MEMS) device was conducted. The nanowire was fabricated using batch process for future integration of nanowires to MEMS sensors or actuators. The tensile specimen of SCS nanowire has a circular cross section of 100 to 200 nm in diameter, 5 μm long. The diameter was controlled by oxidizing 800-nm square cross-section wires fabricated using electron beam lithography. The oxidizing thinning process also reduced the surface roughness. On-chip tensile testing using an electrostatic actuator and sensor was conducted for the specimen of 190 nm in cross-section size. The tensile strength of the wire was 2.6 GPa. The strength and fracture properties were discussed by comparing with a silicon nanowire fabricated using two-step Bosch process to examine the difference in surface finishing.