145-MW/cm2 Heteroepitaxial Diamond MOSFETs With NO2 p-Type Doping and an Al2O3 Passivation Layer

In this study, we investigated diamond metal oxide semiconductor field effect transistors (MOSFETs) with NO
₂
p-type doping and Al
₂
O
₃
passivation layer fabricated on a high-quality heteroepitaxial single crystal (001) diamond substrate called Kenzan diamond
^®
. MOSFETs with a gate length of 1.4
$\mu \text{m}$
and nearly zero source-gate spacing exhibited a high drain current density of −776 mA/mm with a negligible gate leakage current (
$< 0.1~\mu \text{A}$
/mm). MOSFETs with a gate-to-drain length of 4.8
$\mu \text{m}$
delivered a high off-state breakdown voltage (−618 V) at an average breakdown field of 1.2 MV/cm and a specific on-resistance of 2.63
$\text{m}\Omega \cdot $
cm
²
. Baliga’s Figure-Of-Merits was calculated as 145 MW/cm
²
and the anticipated maximum power density was 12 W/mm. The diamond MOSFET was improved with high crystal quality.