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 $hbox{Si}_{1 - x}hbox{C}_{x}$ 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 $x approx hbox{0.01}$ , nMOSFET device performance is enhanced by up to 10%, driving 880 $mu hbox{A}/muhbox{m}$ at 1-V $V_{rm DD}$. It is also demonstrated that the successful implementation of $hbox{Si}_{1 - x} hbox{C}_{x}$ 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 $(C_{rm sub}])$. Furthermore, adding a Si capping layer on top of the $hbox{Si}_{1 - x}hbox{C}_{x}$, greatly improves upon the stressors' stability during the downstream processing and the silicide sheet resistance.