White X-ray Topography of Lattice Undulation in Bonded Silicon-on-Insulator Wafers

The lattice undulation of a silicon-on-insulator (SOI) layer in bonded SOI wafers was observed by synchrotron white and monochromatic X-ray topographies. Pattern formation for white X-ray topography was discussed using the geometric relation among the Bragg streak and diffracted X-rays in reciprocal space. The diffraction images in white X-ray topographs were simulated using the angular distributions of the lattice inclination in SOI layers obtained by the analysis of monochromatic X-ray topographs. The results of this simulation were in very good agreement with observations including the dependences on camera distance and SOI layer thickness, indicating that the contrast is mainly formed by the divergence/convergence effect of the diffracted X-rays.