Tilted epitaxy on (211)-oriented substrates

Spontaneous tilting of lattice mismatched epilayers grown on (211)-oriented substrates has been observed in numerous systems in literature. Here, we have examined a model system, GaSb/Si(211), with two dimensional X-ray diffraction and conventional transmission electron microscopy, and developed a universal model which explains the origin of the tilt phenomenon as the minimization of projected lattice mismatch for low-index planes across the film/substrate interface. The model developed predicts the tilt for lattice mismatches in the range of 0%–20% covering most semiconductor heteroepitaxial systems.