Self-aligned inversion channel In0.53Ga0.47As N-MOSFETs with ALD-Al2O3 and MBE-Al2O3/Ga2O3(Gd2O3) as gate dielectrics

Self-aligned inversion-channel In
_0.53
Ga
_0.47
As n-MOSFETs with ex-situ atomic-layer-deposited Al
₂
O
₃
and in-situ ultra-high-vacuum deposited Al
₂
O
₃
/Ga
₂
O
₃
(Gd
₂
O
₃
) as gate dielectrics have been demonstrated. Both devices exhibit excellent DC characteristics, including high drain currents and transconductances. In addition, RF characteristics of both devices were analyzed; without using any isolation, non dc-embedded current gain cutoff frequency (f
_T
) and maximum oscillation frequency (f
_max
) of ~ 3.1 and 1.1 GHz (ALD-Al
₂
O
₃
) and of ~ 17.9 and 11.2 GHz (MBE-Al
₂
O
₃
/Ga
₂
O
₃
(Gd
₂
O
₃
)), respectively, have been obtained.