We report the growth and characterization of thin (<35nm) germanium-carbon alloy (Ge1−xCx) layers grown directly on Si by ultrahigh-vacuum chemical vapor deposition, with capacitance-voltage and leakage characteristics of the first high-κ/metal gate metal-oxide-semiconductor (MOS) capacitors fabricated on Ge1−xCx. The Ge1−xCx layers have an average C concentration of approximately 1at.% and were obtained using the reaction of CH3GeH3 and GeH4 at a deposition pressure of 5mTorr and growth temperature of 450°C. The Ge1−xCx films were characterized by secondary ion mass spectrometry, atomic force microscopy, x-ray diffraction, and cross-sectional transmission electron microscopy. A modified etch pit technique was used to calculate the threading dislocation density. The x-ray diffraction results showed that the Ge1−xCx layers were partially relaxed. The fabricated MOS capacitors exhibited well-behaved electrical characteristics, demonstrating the feasibility of Ge1−xCx layers on Si for future high-carrier-mobility MOS devices.

We report the growth process and materials characterization of germanium-carbon alloys (Ge 1−x C x ) deposited directly on Si (1 0 0) substrates by ultra-high-vacuum chemical vapour deposition. The Ge 1−x C x films are characterized by transmission electron microscopy, etch-pit density, x-ray diffraction, secondary ion mass spectrometry and electron energy loss spectroscopy. The results show that the films exhibit low threading dislocation densities despite significant strain relaxation. We also present evidence for carbon segregation in the Ge 1−x C x and interpret these results as a strain relaxation mechanism.

We report the growth and materials characterization of thin (<35 nm) germanium-carbon alloy (Ge 1-x C x ) layers grown directly on Si by ultra-high-vacuum chemical vapor deposition. We show that the presence of C atoms is limited to a thin interfacial region at the Si substrate, and interpret this result as a mechanism for strain relief. We also show that the Ge 1-x C x films exhibit remarkably low threading dislocation densities despite significant relaxation.

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