Crystal characterization of GaP epilayer grown on GaAs by atmospheric pressure metalorganic vapor phase epitaxy

The crystal perfection in GaP film grown on GaAs by atmospheric pressure metalorganic vapor phase epitaxy has been studied by the use of double crystal X-ray diffraction, backscattering spectrometry and Raman scattering techniques. By means of the morphology and full-width at half maximum of X-ray diffraction peak for the GaP epilayers, the growth temperature and V/III ratio were optimized. In the temperature range from 720 to 800°C and with the V/III ratio range from 10 to 80, it was concluded that the optimum growth temperature was 800°C with a V/III ratio of approximately 15. The result of backscattering spectrometry revealed that the minimum yield for the GaP epilayer grown under nearly optimized growth conditions exceeded that for a perfect crystal. In addition, the residual strain of GaP epilayer was calculated by using a biaxial stress model and Raman scattering measurement.