Thin Germanium-Carbon Layers on Silicon for Metal-Oxide-Semiconductor Devices

Germanium-carbon alloys (Ge
_1-x
C
_x
) were first deposited on Si (100) by chemical vapor deposition using precursors containing Ge-C bonds. The stated objective of that work was to explore Ge
_1-x
C
_x
as a potentially lattice-matched system with Si capable of bandgap engineering. In step with renewed interest in Ge MOSFET devices due to the advent of high-kappa dielectrics, our group has revisited Ge
_1-x
C
_x
recently, and for the first time demonstrated pMOSFETs with enhanced hole mobility fabricated on thin (30 nm) Ge
_1-x
C
_x
layers deposited directly on Si. This abstract presents previously unreported yet relevant materials-related details of the Ge
_1-x
C
_x
films. The key result is that the Ge
_1-x
C
_x
films exhibit remarkably low threading dislocation densities despite significant strain relaxation