Experimental Investigation of Piezoresistive Effect in p-Type 4H–SiC

This letter presents for the first time the piezoresistive effect in p-type 4H-SiC. Longitudinal and transverse p-type 4H-SiC piezoresistors with a doping concentration of 1018cm-3were fabricated along [1100] directions. Ni/Al electrodes annealed at 1000°C showed a good ohmic contact, and then, the longitudinal and transverse gauge factors were found to be as high as 31.5 and -27.3, respectively. The large gauge factors, attributed to the change of valance energy bands upon application of mechanical strain, and the linear relationship between the resistance change versus induced strain demonstrate the potential of p-type 4H-SiC for mechanical sensing applications.