Deformations in (Al,Ga)As epitaxial layers wafer bonded on dissimilar substrates

Deformations in heteroepitaxial layer stacks of AlGaAs/GaAs grown on GaAs a re measured by triple crystal diffractometry before epitaxial liftoff and a fter subsequent wafer bonding on various substrates (GaAs, glass, Si, and L iNbO3). The tetragonal deformation present in the as-grown layer stack part ially relaxes during epitaxial liftoff. The roughness of the as-grown layer stack gives rise to a bending of the atomic planes after wafer bonding. Th e widths of the x-ray diffraction peaks are used to estimate the misorienta tion of the lattice planes and compared with the atomic force microscopy me asurements of the surface roughness. (C) 2001 American Institute of Physics .