Lattice-Mismatched $\hbox{In}_{0.4}\hbox{Ga}_{0.6} \hbox{As}$ Source/Drain Stressors With In Situ Doping for Strained $\hbox{In}_{0.53}\hbox{Ga}_{0.47}\hbox{As}$ Channel n-MOSFETs

We report the first demonstration of a strained In
_0.53
Ga
_0.47
As channel n-MOSFET featuring
in

situ
doped In
_0.4
Ga
_0.6
As source/drain (S/D) regions. The
in

situ
silicondoped In
_0.4
Ga
_0.6
As S/D was formed by a recess etch and a selective epitaxy of In
_0.4
Ga
_0.6
As in the S/D by metal-organic chemical vapor deposition. A lattice mismatch of ~ 0.9% between In
_0.53
Ga
_0.47
As and In
_0.4
Ga
_0.6
As S/D gives rise to lateral tensile strain and vertical compressive strain in the In
_0.53
Ga
_0.47
As channel region. In addition, the
in

situ
Si-doping process increases the carrier concentration in the S/D regions for series-resistance reduction. Significant drive-current improvement over the control n-MOSFET with Si-implanted In
_0.53
Ga
_0.47
As S/D regions was achieved. This is attributed to both the strain-induced band-structure modification in the channel that reduces the effective electron mass along the transport direction and the reduction in the S/D series resistance.