Deep trap characterization of Al./sub 48/In./sub 52/As/In/sub .52/(Ga/sub .7/Al/sub .3/)/sub .48/As heterostructures

Electron traps in AlInAs/In/sub .52/(Ca/sub 1-x/Al/sub x/)/sub .48/As (x=0.3) heterostructures are investigated by deep level transient spectroscopy. Two dominant traps with activation energies of 0.31 and 0.59 eV are observed in quaternary and ternary layers respectively. Both these levels are supposed to be intrinsic defects from the same origin. Another defect at E/sub c/-0.4 eV is detected at the AlInAs/InCaAlAs interface. The concentration of this trap is found to be non uniformly distributed on the wafer and possible impurity contamination is suggested.