Defect reduction in GaAs/Si film with InAs quantum-dot dislocation filter grown by metalorganic chemical vapor deposition

The growth of GaAs epilayers on silicon substrates with multiple layers of InAs quantum dots（QDs） as dislocation filters by metalorganic chemical vapor deposition（MOCVD） is investigated in detail.The growth conditions of single and multiple layers of QDs used as dislocation filters in GaAs/Si epilayers are optimized.It is found that the insertion of a five-layer InAs QDs into the GaAs buffer layer effectively reduces the dislocation density of GaAs/Si film.Compared with the dislocation density of 5×107 cm-2 in the GaAs/Si sample without QDs,a density of 2×106 cm-2 is achieved in the sample with QD dislocation filters.