Effect of native oxides on the elasticity of a silicon nano-scale beam

Native oxide is usually formed during the fabrication of silicon beams. A model is developed to describe the effect of native oxide on the elastic modulus of the silicon nano-beam based on the semi-continuum method. The model predicts that Young’s modulus of the nano-beam with native oxide increases as the nano-beam thickness decreases while it exhibits opposite behavior without native oxide. Native oxide dominates the beam with its scaling down to several nanometers. Young’s moduli are in the range from 123 GPa to 190 GPa when the thickness is several nanometers, and they approach the bulk value when the thickness is greater than about 500nm.