Kinetic modeling of N incorporation in GaInNAs growth by plasma-assisted molecular-beam epitaxy

We have studied the growth of GaInNAs by a plasma-assisted molecular-beam epitaxy (MBE). It was found that the N-radicals were incorporated into the epitaxial layer like dopant atoms. In the range of 400–500 °C, the growth temperature (Tg) mainly affected the crystal quality of GaInNAs rather than the N concentration. The N concentration dropped rapidly when Tg exceeded 500 °C. Considering N desorption alone is insufficient to account for the strong falloff of the N concentration with Tg over 500 °C, the effect of thermally-activated N surface segregation must be taken into account. The N concentration was independent of the arsenic pressure and the In concentration in GaInNAs layers, but inversely proportional to the growth rate. Based on the experimental results, a kinetic model including N desorption and surface segregation was developed to analyze quantitatively the N incorporation in MBE growth.