Isotropic piezoresistance of p-type 4H-SiC in (0001) plane

In this work, the isotropic piezoresistance in the (0001) plane of p-type 4H-SiC was discovered by means of the hole energy shift calculation and the coordinate transformation. These results were also confirmed by the measurement of the piezoresistance using a bending beam method. The fundamental longitudinal and transverse piezoresistive coefficients π₁₁ and π₁₂ were found to be 6.43 × 10⁻¹¹Pa⁻¹ and −5.12 × 10⁻¹¹Pa⁻¹, respectively. The isotropy of the piezoresistance in the basal plane of p-type 4H-SiC is attributed to the isotropic hole energy shift under uniaxial strain. This interesting phenomenon in p-type 4H-SiC is promising for the design and fabrication of mechanical sensors and strain-engineered electronics since high sensitivity and consistent performance can be achieved regardless of the crystallographic orientation.