Lattice misfit and relative tilt of lattice planes in semiconductor heterostructures

High resolution X-ray diffraction has been used to investigate the relative tilt between epilayer and substrate lattice planes of different semiconductor heterostructures. All epilayers were grown on (001) GaAs substrates misoriented by 2 degrees towards the next (011) direction. Results on the amount of the relative tilt and the direction of the maximum relative tilt are presented. The authors find that for heterostructures with small misfit (f<0.001) the direction relative tilt coincides with the direction defined by the miscut substrate. In heterostructures with large misfit (f>0.05) an angle of about 90 degrees between the direction of maximum relative tilt and the direction of the miscut substrate has been observed.