Triple-axis X-ray diffraction (TAD) along with synchrotron radiation double-crystal topography (SRDT) is first time employed to investigate Si/SiGe/Si heterostructures on a bonded silicon-on-insulator (SOI) wafer. (004) TAD measurements present the crystallographic misalignment of the whole structure and the two diffraction peaks from the Si layers (i.e. the Si capping layer, the Si buffer and the SOI top Si layer) with the shift in Bragg angle. The bulk Si peak, the Si layers peak, and the SiGe layer peak oil the SRDT (004) rocking curves are discerned, respectively. The asymmetry of the Si layers peak is attributed to the slight difference in lattice spacing and the little crystallographic misalignment. The two diffraction peaks with the shift in Bragg angle are identified from the Si capping layer and the underlying Si layers (i.e. the Si buffer and the SOI top Si layer). (004) symmetrical and (1 13) asymmetrical diffraction measurements demonstrate that the tensile strain and Ge diffusion result into the shift in Bragg angle of the Si layers. (c) 2006 Elsevier B.V. All rights reserved.