Low-temperature growth of Ge1 − xSnx thin films with strain control by molecular beam epitaxy

Abstract High-quality Ge 1 − x Sn x thin films on InGaAs buffer layers have been demonstrated using low-temperature growth by molecular beam epitaxy. X-ray diffraction and secondary ion mass spectrometry are used to determine the strain and Sn concentration. Up to 10.5% Sn has been incorporated into the Ge 1 − x Sn x thin film without Sn precipitation, as verified by transmission electron microscopy. Roughened surfaces are found for tensile strained Ge 1 − x Sn x layers.