Effect of ionization and acceleration of as-source beam on structural properties of low temperature grown GaAs

Single-crystal GaAs films were grown on semi-insulating GaAs (100) at substrate temperatures below 200°C by using ionized source beam epitaxy. The correlation between the properties of the films and the growth parameters, in particular, the substrate temperature, the amount of As-source beam ionization, and the acceleration voltage of the As beam was investigated to elucidate the possible benefits of source beam ionization and acceleration on low-temperature thin film growth. The use of ionized and accelerated As-source beam greatly improved the quality of the low-temperature grown GaAs film. The surface morphology, crystallinity, and microstructure of the low temperature grown GaAs films were evaluated using in-situ reflection high energy electron diffraction, double crystal X-ray diffraction, and cross section transmission electron microscopy.