High-Breakdown P-Channel GaN MOS-HFETs With Al₂O₃-Dielectric and Drain Field-Plate

Abstract

This work reports record-high three-terminal on-state drain-source breakdown voltage $(BV_{DS})$ of −735 V in p-channel GaN metal-oxide-semiconductor heterostructure field-effect transistors (MOS-HFETs) with a drain field-plate (DFP). High-k and wide-gap Al2O3 was deposited as the gate oxide and surface passivation by using a non-vacuum ultrasonic spray pyrolysis deposition (USPD) technique. Good source/drain ohmic contacts were obtained by devising an Mg-doped p++-GaN capper. Enhanced two-dimension hole gas (2DHG) characteristics and current densities have also been achieved by the devised p-GaN/GaN/AlN/Al0.3Ga0.7N heterostructure. The present p-channel GaN MOS-HFET design with (without) DFP has demonstrated superior on/off current ratio $(I_{on}/I_{off}$ ) of $2\times 10^{6}$ ( $9.2\times10\,\,^{\mathrm{ 5}}$ ), maximum drain-source current density $(I_{DS, max})$ of −9.5 (−10.6) mA/mm at $V_{DS}\,\,=$ 20 V, two-terminal off-state gate-drain breakdown voltage $(BV_{GD})$ of 710 (520) V, and $BV_{DS}$ of −735 (−545) V, respectively. The present design is suitable for applications in high-voltage complementary power-switching circuits of electric vehicle (EV) electronics.

Keywords

• P-channel
• GaN
• MOS-HFET
• non-vacuum ultrasonic spray pyrolysis deposition
• Al₂O₃
• drain field-plate