1300 V Normally-OFF p-GaN Gate HEMTs on Si With High ON-State Drain Current

In this article, we demonstrate normally-OFF p-GaN gate high electron mobility transistors (HEMTs) on Si with an ultrahigh breakdown voltage (
${V}_{BR}$
) and excellent saturation drain current. Benefiting from the optimized material growth of high-resistivity buffer, effective Al
₂
O
₃
surface passivation with suppressed OFF-state leakage current, and proper management of the electric field on the p-GaN gate edge, the device with a gate–drain distance of
$18.5~\mu \text{m}$
exhibits a
${V}_{BR}$
of 1344 V at
${I}_{D}$
of
$1~\mu \text{A}$
/mm with grounded substrates, the highest among all the reported normally-OFF GaN-on-Si transistors. Well-restored high-density 2-D electron gas and efficient gate modulation enable the device with a high
${I}_{DS,max}$
of 450 mA/mm and a low specific ON-resistance of 3.92
$\text{m}\Omega \cdot $
cm
²
. Moreover, a large threshold voltage of 1.6 V (at
${I}_{D}$
of
$10~\mu \text{A}$
/mm) and a steep subthreshold slope of 66 mV/dec have been achieved, with negligible threshold voltage shift upon long-term forward gate stress at 150 °C. These results illustrate the great potential of p-GaN gate HEMTs on Si for beyond 600-V applications.