P-Channel HFET Utilizing 2D Hole Gas in Si-Face 3C/4H-SiC Heterostructure

A p-channel heterojunction field effect transistor (HFET) utilizing 2D hole gas (2DHG) in a Si-face 3C/4H-SiC heterostructure was demonstrated for the first time. A 36-nm-thick undoped single-crystal 3C-SiC layer was epitaxially grown on a step-controlled Si-face 4H-SiC substrate by thermal chemical vapor deposition. The presence of 2DHG at the 3C/4H heterointerface was confirmed by Hall effect measurements. At room temperature, the measured hole mobility and sheet carrier density were 30 cm2/Vs and ${1}.{6}\times {10} ^{{13}}$ cm-2, respectively. The hole density is temperature-independent between 78 and 293 K owing to the nature of polarization-induced carriers. P-channel HFETs were fabricated in the 3C/4H heterostructure, and transistor operation with a high-current conductivity of 66.2 mA/mm were also demonstrated.