The strain model of misfit dislocations at Ge/Si hetero-interface

The misfit dislocation at Ge/Si hetero-interface was quantitatively investigated by a combination of highresolution transmission electron microscopy and geometric phase analysis. To describe the strain field around the misfit dislocation core at Ge/Si hetero-interface more accurately, a modified Foreman model is proposed by introducing a new half width of the misfit dislocation core into the original Foreman model. The experimentally measured strain field around the misfit dislocation core at Ge/Si hetero-interface was compared with the theoretical strain field calculated by the modified Foreman model. It is demonstrated that the modified Foreman model with the variable factor a = 2 is a perfect strain model of misfit dislocation at Ge/Si hetero-interface.