Total Ionizing Dose (TID) Effects in GaAs MOSFETs With La-Based Epitaxial Gate Dielectrics

Epitaxially grown La-based oxide has shown promise as a gate dielectric for GaAs substrate materials with a low interface trap density in the mid to low
$10^{11}$
cm
$^{\mathrm {-2}}$
eV
$^{\mathrm {-1}}$
range. Total ionizing dose (TID) effects have been studied on GaAs MOSFETs with Al
₂
O
₃
/La
₂
O
₃
and Al
₂
O
₃
/La
_1.8
Y
_0.2
O
₃
gate oxides. Charge trapping mechanisms in GaAs MOSFETs are studied by the AC transconductance dispersion method. Al
₂
O
₃
/La
₂
O
₃
gated devices show a combination of electron and hole trapping, whereas Al
₂
O
₃
/La
_1.8
Y
_0.2
O
₃
gated devices show primarily hole trapping.