Investigation of the interface grading in III-V heterostructures by double-crystal diffractometry

The interface grading in III-V compound single heterostructures has been investigated by using the double-crystal diffractometry. Theoretical rocking curves have been calculated for the particular example of InGaAs/InP slightly mismatched heterostructures, assuming the 004 reflection and the CuK?1 radiation. It has been found that the Pendellosung fringe intensity is the most suitable and sensitive parameter to determine the type and amount of the lattice parameter gradient close to the interface. Rocking curves have been experimentally measured for a variety of single heterostructures and a satisfactory agreement between experimental and theoretical profiles has been obtained when the correct interface shape was assumed.