Study of growth temperature effect on crystal structure transition for GaN films grown on GaAs by metalorganic vapor phase epitaxy

A series of GaN films were grown on (001) GaAs substrate by metalorganic vapor phase epitaxy from 500 to 1000 °C. Our experiments indicate that the cubic GaN structure can be improved by increasing growth temperature based on the results of both X-ray diffraction and Raman measurements. Moreover, the spatial correlation model is also employed to calculate the correlation length for phonon transmission in the crystal. The corresponding correlation length of GaN on GaAs is compatible to those of conventional semiconductors, including BN, ZnSe and AlGaAs. All of the findings suggest that a good cubic GaN crystalline film can be synthesized when a thermally stable cubic substrate is available.