Properties of pseudomorphic InxGa1-xAs/Al0.3Ga0.7As/GaAs high electron mobility transistors - 0 is smaller than x smaller than 0.5.

Modulation doped Al sub 0.3 Ga sub 0.7 As/In sub x Ga sub 1-x As/GaAs high electron mobility transistor structures for device application have been grown using molecular beam epitaxy. Initially the critical layer thickness for InAs mole fractions up to 0.5 was investigated. For InAs mole fractions up to 0.35 good agreement with theoretical considerations was observed. For higher InAs mole fractions disagreement due to a strong decrease of the critical layer thickness was observed. Using the molecular beam epitaxy technology Al sub 0.3 Ga sub 0.7 As/In sub x Ga sub 1-x As/GaAs high electron mobility transistor structures with InAs mole fractions between 0 and 0.35 were grown for device applications. For the presented field effect transistors best device performance is obtained for InAs mole fraction in the range of 0.25-0.3.