Control of domain orientation during the MBE growth of ZnTe on a-plane sapphire

ZnTe epilayers were grown on transparent a-plane (11-20) sapphire substrates by molecular beam epitaxy (MBE). The insertion of a low-temperature nucleated buffer layer was carried out, and the influence of the buffer layer annealing prior to the film growth on crystallographic properties of the epilayer was investigated. Pole figure imaging and wide-range reciprocal space mapping (RSM) measurements were used to study the domain distribution within the layer, and epitaxial relationships between the ZnTe thin films and the sapphire substrates. The orientation of ZnTe domains formed on a-plane sapphire substrates was controlled by the annealing condition of the buffer layer. Two different {111} domains were formed from the sample the buffer layer was annealed at 350 °C, while (100) layers were obtained from the sample the buffer layer was annealed at 300 °C. These crystallographic features were probably originated from the atom arrangements of ZnTe and sapphire at the interface.