High-voltage accumulation-mode lateral RESURF GaN MOSFETs on SiC substrate

Lateral, accumulation-mode gallium nitride (GaN) MOSFETs were fabricated on a silicon-doped GaN epilayer on a AlGaN isolation layer on a conducting 6H-SiC substrate. The polysilicon gate was formed over a 100 nm silicon dioxide gate dielectric deposited by low-pressure chemical vapor deposition at 900/spl deg/C. The accumulation-layer field-effect mobility is measured to be 110 cm/sup 2//V-s. GaN MOSFETS with a 9 /spl mu/m RESURF length were characterized with an on-resistance of 140 m/spl Omega/-cm/sup 2/ at V/sub GS/=15 Volts and breakdown voltage /spl les/180 Volts attributed to tunneling through the AlGaN isolation layer.