In this study, a 6 nm layer of Magnesium Silicate (Mg-Silicate) was deposited
on AlGaN/GaN heterostructure by sputtering of multiple stacks of MgO and
SiO2β, followed by rapid thermal annealing in a nitrogen (N2β)
environment. The X-ray photoelectron spectroscopy (XPS) analysis confirmed the
stoichiometric Mg-Silicate (MgSiO3β) after being annealed at a temperature
of 850 βC for 70 seconds. Atomic force microscopy (AFM) was employed to
measure the root mean square (RMS) roughness (2.20 nm) of the Mg-Silicate. A
significant reduction in reverse leakage current, by a factor of three orders
of magnitude, was noted for the Mg-Silicate/AlGaN/GaN metal-oxide-semiconductor
(MOS) diode in comparison to the Schottky diode. The dielectric constant of
Mg-Silicate(EMgβSilicateβ) and the interface density of states
(Ditβ) with AlGaN were approximated at βΌ 6.6 and 2.0 Γ
1013 cmβ2eVβ1 respectively, utilizing capacitance-voltage (CV)
characteristics