Valence band offsets at strained Ge/Sb/Si(100) and Ge/H/Si(100) interfaces

We report x-ray photoelectron spectroscopy experimental results on band offsets at Ge=Si.100/2 1 interfaces grown by hydrogen and Sb-surfactant mediated epitaxy. For Ge deposited at 400 C in Si.100/2 1, the valence band discontinuity was of 0:72 0:07 eV. Using atomic hydrogen and a Sb-monolayer mediated growth, we obtained values of 0:75 0:07 and 0:69 0:07 eV. Our data show that the surfactant Ge layer strain induced effects on the modification of band offsets are surprisingly negligible.