Silane and Ammonia Surface Passivation Technology for High-Mobility $\hbox{In}_{0.53}\hbox{Ga}_{0.47}\hbox{As}$ MOSFETs

We report the integration of silane and ammonia (SiH
₄
+ NH
₃
) surface passivation technology to realize high-quality gate stack on a high-mobility In
_0.53
Ga
_0.47
As compound semiconductor. Vacuum anneal at 520°C desorbs the native oxide while preserving the surface morphology and material composition of In
_0.53
Ga
_0.47
As. By incorporating SiH
₄
+ NH
₃
passivation, a thin silicon oxynitride (SiO
_x
N
_y
) interfacial layer was formed during high-
k
dielectric deposition. In
_0.53
Ga
_0.47
As n-MOSFETs with SiH
₄
+ NH
₃
passivation demonstrate significantly reduced subthreshold swing and off-state leakage current
I

_off
in comparison with control In
_0.53
Ga
_0.47
As n-MOSFETs without passivation. This is due to significant reduction of interface state density
D

_it
. Improvement in carrier mobility over the control In
_0.53
Ga
_0.47
As n-MOSFETs was also achieved with SiH
₄
+ NH
₃
passivation.