C-V characterization of the piezocapacitive effect with a microfabricated cantilever

The piezocapacitve effect of an n-type MOS capacitor is experimentally studied with a micro-fabricated cantilever. It shows that besides the geometrical effect, the stress induced dielectric constant change also contributes to the piezocapacitive behavior. To evaluate the stress effect on the dielectric constant of the thermal SiO2, an improved analytical model is developed and capacitance-voltage (C-V) measurements are used to investigate the dielectric constant changes in detail. The stress effect on the dielectric constant was characterized by the dielectrostriction coefficient M12. According to the measurements, the dielectrostriction coefficient M12 of the thermal SiO2 is −(0.21±0.01)×10⁻²¹ m²/V².