Strain Enhanced nMOS Using In Situ Doped Embedded $\hbox{Si}_{1 - x}\hbox{C}_{x}$ S/D Stressors With up to 1.5% Substitutional Carbon Content Grown Using a Novel Deposition Process

This letter reports on the implementation of high carbon content and high phosphorous content Si
_1-x
C
_x
layers in the source and drain regions of n-type MOSFET in a 65-nm-node integration scheme. The layers were grown using a novel epitaxial process. It is shown that by implementing stressors with
x
ap 0.01, nMOSFET device performance is enhanced by up to 10%, driving 880 muA/mum at 1-V
V

_DD
. It is also demonstrated that the successful implementation of Si
_1-x
C
_x
relies on the careful choice of integration and epitaxial layer parameters. There is a clear impact of the postepitaxial implantation and thermal treatment on the retained substitutional C content ([
C

_sub
]). Furthermore, adding a Si capping layer on top of the Si
<sub>1

-x</sub>
C
_x
, greatly improves upon the stressors' stability during the downstream processing and the silicide sheet resistance.