Low-defect-density germanium on silicon obtained by a novel growth phenomenon

Heteroepitaxial Ge on Si has been grown using molecular beam epitaxy at a Si substrate temperature of 900 °C. Electron microscopy results reveal a highly faceted interface, indicating localized Ge melting and subsequent local alloying with Si. Furthermore, this phenomenon is associated with extensive threading dislocation confinement near the Ge/Si interface. Etch pit density measurements obtained on Ge heteroepitaxial films that have undergone interfacial melting are as low as 105 cm−2.