Transmission electron microscopy and synchrotron radiation double-crystal topography (SRDT) were employed to investigate Si/SiGe/Si heterostructures grown by ultra-high vacuum chemical vapour deposition (UHVCVD) on bonded Si-on-insulator (SOI) wafers. A configuration of misfit dislocation dipoles was observed by high-resolution transmission electron microscopy (HRTEM). The dislocation dipoles were mostly of 60° type and three types of 60° dislocation dipoles, extrinsic, intrinsic, and null, were presented. Dark-field images (DFIs) indicated no lateral compositional modulations but strain distribution appearing in the SiGe layer, which was supported by the SRDT topograph. It was suggested that the lateral strain modulation in the SiGe layer and subsequent annealing play an important role in the introduction of the dislocation dipoles.

Misfit Dislocation Dipoles in Si/SiGe/Si Heterostructures on SOI. T.Ma, H.Tu, B.Shao, A.Liu, G.Hu: Materials Science in Semiconductor Processing, 2006, 9[1-3], 49-52