Piezoresistive transduction optimization of p-doped poly-Silicon NEMS

This paper presents a thorough investigation of the longitudinal gauge factor (GF) at high doping level in columnar polycrystalline-Silicon (poly-Si) nanowire (NW) NEMS devices. It is shown that a high GF (more than 30) can be obtained with concentration about 10²⁰ cm^-3. This result is very promising for high volume, low fabrication cost NEMS devices. This high GF is due to the specific piezoresistive behavior of poly-Si when compared to c-Si. We modeled the mechanical properties of the poly-Si and compared them to electrical measurements in order to predict the optimum dopant concentration for high GF. The experimental extraction of the GF has been performed directly on NWs gauge thanks to a new non-destructive method presented in [1].