(AlGa)As grown by low pressure metalorganic vapor phase epitaxy using a N2 carrier

We have studied the growth of Al_xGa_1−xAs (0.24<x<0.34) using a N₂ carrier in low pressure metalorganic vapor phase epitaxy. Growth temperature, gas velocity, and V/III ratio were varied to achieve optimum growth conditions. Layers with excellent morphology and electrical and optical properties comparable to samples grown using standard conditions (with a H₂ carrier) can be deposited in a nitrogen ambient. Al_0.24Ga_0.76As bulk material grown on an AlAs buffer layer with a background doping of 1.3×10¹⁶ cm⁻³ showed Hall mobilities of 4500 and 2300 cm²/Vs at 77 and 300K. Photoluminescence studies at 2K revealed strong bound exciton transitions with a full width at half maximum of 5.2 meV for Al_0.29Ga_0.71AS.