Extraction of interface state density and resistivity of suspended p-type silicon nanobridges

The evaluation of the influence of the bending deformation of silicon nanobridges on their electrical properties is crucial for sensing and actuating applications. A combined theory/experimental approach for determining the resistivity and the density of interface states of the bending silicon nanobridges is presented. The suspended p-type silicon nanobridge test structures were fabricated from silicon-on-insulator wafers by using a standard CMOS lithography and anisotropic wet etching release process. After that, we measured the resistance of a set of silicon nanobridges versus their length and width under different bias voltages. In conjunction with a theoretical model, we have finally extracted both the interface state density of and resistivity suspended silicon nanobridges under different bending deformations, and found that the resistivity of silicon nanobridges without bending was 9.45 mΩ·cm and the corresponding interface charge density was around 1.7445 × 1013 cm−2. The bending deformation due to the bias voltage slightly changed the resistivity of the silicon nanobridge, however, it significantly changed the distribution of interface state charges, which strongly depends on the intensity of the stress induced by bending deformation. (semiconductor physics)