Arsenic incorporation into InGaAsP grown by low-pressure metalorganic vapor phase epitaxy using tertiarybutylarsine and tertiarybutylphosphine in N2 ambient

In x Ga 1−x As y P 1−y epilayers have been grown by low-pressure metalorganic vapor phase epitaxy (LPMOVPE) using tertiarybutylarsine (TBA) and tertiarybutylphosphine (TBP) as group V precursors and nitrogen as the carrier gas. Arsenic incorporation into InxGa1−xAsyP1−y films grown by LPMOVPE as a function of the gas phase composition ratio and V/III ratio has been systematically studied. With optimized growth conditions, the arsenic composition of the epilayers does not change linearly with the TBA source flow. It is observed that the arsenic incorporation becomes saturated when the gas phase composition TBA/(TBA+TBP) increases to 0.4. The incorporation kinetics in MOVPE growth of InxGa1−xAsyP1−y alloy has been analyzed by using an adsorption-trapping model. The As composition (y) of the InxGa1−xAsyP1−y films varies with the TBA gas phase composition ξ=TBA/(TBA+TBP) according to the expression y=2Ns*/aN0(1−e−θβξ). It is demonstrated that with the optimized growth conditions, TBA has a higher incorporation efficiency than TBP in MOVPE growth of InxGa1−xAsyP1−y films.