Multi-Channel Tri-Gate GaN Power Schottky Diodes With Low ON-Resistance

In this letter, we demonstrate high-performance lateral GaN power Schottky barrier diodes based on a novel multi-channel tri-gate architecture. A significant reduction in ON-resistance (
${R}_{ \mathrm{\scriptscriptstyle ON}}$
) of 50%, down to
$7.2 \pm 0.4~\Omega \cdot {\mathrm {mm}}$
, along with a much smaller forward voltage (
${V}_{\mathrm {F}}$
) of 1.57 ± 0.06 V, were achieved with multiple 2DEG channels (multi-channels) formed by periodic AlGaN/GaN heterostructures. We used a tri-anode structure to form Schottky contact to the multi-channels through the fin sidewalls, leading to a small turn- ON voltage (
${V}_{ \mathrm{\scriptscriptstyle ON}}$
) of 0.67 ± 0.04 V. To simultaneously control the multi-channels and effectively spread the electric field in OFF state, a tri-gate structure was integrated in the anode, resulting in an ultra-low leakage current (
${I}_{\mathrm {R}}$
) of ~1 nA/mm at −600 V and a high breakdown voltage (
${V}_{\mathrm {BR}}$
) of −900 V at
$1~\mu$
A/mm with grounded substrate. In addition, the devices presented promising switching performance, due to the small product of
${R}_{ \mathrm{\scriptscriptstyle ON}}$
and reverse charge (
${Q}$
), thanks to the optimized tri-gate geometry, and high effective mobility (
$\mu _{\mathrm {e}}$
) of 2063 ± 123 cm
²

$\cdot $
V
⁻¹
s
⁻¹
despite the small fin width (
${w}$
) of 50 nm. Our approach combines in a unique way the excellent electrostatic control of the tri-gate structure with the high conductivity of multi-channels, offering a promising platform for future advances in GaN power devices.