Measuring the nonlinearity of silicon piezoresistance by tensile loading of a submicron diameter fiber using a microinstrument

This report presents a mechanical loading experiment utilizing a microelectromechanical system microinstrument in which we stretched a 150 nm diameter n-type silicon fiber above 1% strain at room temperature and measured the longitudinal piezoresistive effect. The piezoresistive effect at these strains has not been measured. Piezoresistive coefficients up to the third order are required to fit the 0% to 1% strain measurement data with high statistical confidence. Our first-order coefficient matches results that are published in literature. However, compared with published second-order piezoresistive coefficients, the highest-order coefficient available, our result differs in magnitude and sign. Our analysis suggests that previously published second-order piezoresistive coefficients are not reliable due to limited data measured at small strain values (<0.1%), where the second-order piezoresistive effect is small. (C) 2004 American Institute of Physics.