Growth of tensile-strained Ge layer and highly strain-relaxed Ge1−xSnx buffer layer on silicon by molecular beam epitaxy

Highly strain-relaxed Ge
_1-x
Sn
_x
layers were grown directly on Si(100) by MBE firstly. XRD and AFM measurements demonstrate a good crystalline quality and a relatively flat surface. Ge with 0.82% tensile strain were grown on the Ge
_0.895
Sn
_0.105
/Si, and the tensile-strain value decreases with increasing thickness of Ge epilayers.