Theoretical and experimental study on epitaxial growth of antiphase boundary free GaAs on hydrogenated on-axis Si(001) surfaces

The formation of double-layer atomic steps on Si(001) surfaces is an efficient way to eliminate the antiphase boundaries (APBs) on GaAs/Si(001) interfaces. The surface energy of on-axis Si(001) surfaces with different atomic step structures was calculated and analyzed from the first principles. An optimal hydrogen-annealing process condition, the hydrogen pressure of 800 mbar and the annealing temperature of 800 °C for 10 min, was obtained experimentally. Under this annealing condition, a 420 nm APB-free GaAs epitaxial layer grown on on-axis Si(001) substrates was achieved by metal-organic chemical vapor deposition. The effect of the annealing temperature on the APB density of the GaAs/Si(001) samples was explained from the aspects of thermodynamics and kinetics. It is of great significance to optimize the growth conditions of APB-free III–V epitaxial materials on on-axis Si(001) surfaces for the large-scale silicon monolithic integration of optoelectronic devices.