Effect of growth conditions on the electrical and optical properties of AlxIn1−xAs (0.48<x<0.7)‐Ga0.47In0.53As heterostructures

An increase of the Al‐ content of AlInAs layers above that of the composition which is lattice matched to InP (Al0.48In0.52As) has been shown to lead to increased Schottky barrier height [Lin et al., Appl. Phys. Lett. 49, 1593 (1986)]. This technique has been used to realize improved gate‐to‐drain breakdown voltage in AlInAs‐GaInAs modulation‐doped transistors designed for power applications. This letter reports the observation of an optimum growth temperature regime for the Al‐rich Schottky layers in the modulation‐doped structure. Growth in this regime results in the highest conductivity for modulation‐doped structures as well as the highest quality interface formation as determined from low temperature photoluminescence measurements.