A kinetic model for As and P incorporation behaviors in GaAsP grown by gas-source molecular beam epitaxy

A kinetic model has been developed to explain As and P incorporation behaviors in GaAs1−xPx epilayers grown on GaAs (001) by gas-source molecular beam epitaxy. The model can predict the P compositions for various substrate temperatures and flow rates. The model shows that an in situ determination of GaP molar fraction in GaAs1−xPx can be performed by group V-induced intensity oscillations of reflection high-energy-electron diffraction at low substrate temperatures where desorption of group V species is negligible. At high substrate temperatures the compositions can be determined from the arsine and phosphine flow rates.