High-cycle fatigue test of nanoscale Si and SiO/sub 2/ wires based on AFM technique

This paper focuses on revealing the effects of specimen size, frequency and temperature on fatigue lives of nanoscale single crystal silicon (SC-Si) and silicon dioxide NOD wires for reliable design of micro/nano electro-mechanical systems (MEMS/NEMS). Evaluation of fatigue lives for nanoscale fixed-fixed SC-Si and SiO/sub 2/ wires was performed by stress-controlled cyclic bending tests under an atomic force microscope (AFM) at temperatures ranging from 295 K to 573 K. In MEMS-00 and MEMS-01, the quasi-static bending tests under the AFM for nanoscale SC-Si wires were reported, which discussed the effect of specimen size on elastic/plastic deformation behavior of the wires at intermediate temperatures. Here, we exhibit high-cycle fatigue lives of nanoscale SC-Si and SiO/sub 2/ specimens. The specimen size produced a large effect on fatigue life, but frequency and temperature dependences were not observed. The 200 nm-wide SC-Si wires had the fatigue lives of 10/sup 1/-10/sup 2/ times longer than those for 550 nm-wide wires at the same stress level. This research newly proposes fatigue life criteria for nanoscale SC-Si and SiO/sub 2/ specimens using a power law.