Atom probe tomography study on Ge1−x−ySnxCy hetero-epitaxial film on Ge substrates

We analyzed the incorporation of C atoms into a ternary alloy Ge 1 − x − y Sn x C y epitaxial film on Ge substrates on a sub-nanometer scale by using atom probe tomography. Periodic atom distributions from individual (111) atomic planes were observed both in the Ge 1 − x − y Sn x C y film and at the Ge substrates. Sn/C atoms had non-uniform distributions in the film. They also demonstrated a clear positive correlation in their distributions. Substitutional C atoms were only incorporated into the film when an Sn atom beam was applied onto the substrates under film growth conditions.