It was found that the surface migration and nucleation behaviour of InSb quantum dots on AlSb/Si substrates, formed by molecular beam epitaxy in Stranski–Krastanov growth mode, were dependent upon the substrate temperature. At above 430C, quantum dots migrated and preferentially assembled onto the surface steps of high defect AlSb layers grown onto Si substrates, while they were uniformly distributed on the surface at below 400C. It was also found that quantum dots located on the defect sites led to the effective termination of the propagation of micro-twin induced structural defects into overlying layers; resulting in low-defect material grown onto a largely mismatched substrate. The resultant 1.0µm-thick Alx Ga1− xSb (x = 0.8) layer grown onto the silicon substrate exhibited atomically flat (0.2nm AFM mean roughness) surfaces and high crystal quality.

The Growth of a Low Defect InAs HEMT Structure on Si by using an AlGaSb Buffer Layer Containing InSb Quantum Dots for Dislocation Termination. K.M.Ko, J.H.Seo, D.E.Kim, S.T.Lee, Y.K.Noh, M.D.Kim, J.E.Oh: Nanotechnology, 2009, 20[22], 225201