Behavior of Misfit Dislocations in GaAs Epilayers Grown on Si at Low Temperature by Molecular Beam Epitaxy

This is the authors' abstract. We don't add key points for this paper.

The behavior of misfit dislocations in GaAs buffer layers grown on Si was investigated by the measurement of stresses using optical interferometry and X-ray diffraction. The buffer layers grown at 250°C with various thicknesses (0.05∼0.20 µm) were annealed at various temperatures (400∼600°C). The overlayers were grown at 300°C. With increasing annealing temperature or thickness, the stresses changed from compressive to tensile. The stress-free GaAs/Si wafer was produced with a 0.10-µm-thick buffer layer annealed at 500°C. These results indicate that in low-temperature growth, it is important to optimize both the annealing temperature and the thickness of the buffer layer. In addition, the asymmetric stresses were observed between [011] and [01̄1]. This asymmetry was caused by the difference in dislocation velocities or nucleation energies between α- and β-dislocations.