Electrical Characterization and Materials Stability Analysis of ${\rm La}_{2}{\rm O}_{3}/{\rm HfO}_{2}$ Composite Oxides on n-${\rm In}_{0.53}{\rm Ga}_{0.47}{\rm As}$ MOS Capacitors With Different Annealing Temperatures

In this letter, a high-k composite oxide composed of La
₂
O
₃
and HfO
₂
is investigated for n-In
_0.53
Ga
_0.47
As metal-oxide-semiconductor (MOS) capacitor application. The composite oxide was formed by depositing five layers of La
₂
O
₃
(0.8 nm)/HfO
₂
(0.8 nm) on InGaAs with post deposition annealing at 500°C. The MOS capacitors fabricated show good inversion behavior, high capacitance, low leakage current, with excellent interface trap density (D
_it
) of 7.0×10
¹¹
cm
^-2
eV
^-1
, small hysteresis of 200 mV and low capacitance equivalent thickness of 2.2 nm at 1 kHz were also achieved.