Monte Carlo investigation of the influence of V/III flux ratio on GaAs/GaAs(001) submonolayer epitaxy

The influence of the V/III flux ratio on the submonolayer growth of GaAs on the GaAs (001) surface is simulated by the Monte Carlo method. Growth is carried out using the method of molecular beam epitaxy at different values of process parameters. The surface density of islands against the V/III flux ratio is calculated. The saturation value of the surface density at 580$^\circ$C is found to be 2 $\times$ 10$^{12}$ cm$^{-2}$, which is in agreement with the experimental data. The V/III flux ratio influences the island density most strongly at a reduced temperature (550$^\circ$C) and an elevated growth rate (a monolayer per second), when the arsenic desorption is weak. The fraction of arsenic atoms in the growing film is estimated under different process conditions. It has been shown that, as the surface coverage rises, the influence of the V/III flux ratio on the fraction of arsenic atoms becomes weaker.