Abstract
In this work we investigated the dislocation-dependent behavior of Pendellösung fringes from two types of semiconductor heterostructures: a uniform-composition InGaAs epitaxial layer grown on a GaAs (001) substrate with an intermediate step-graded InGaAs buffer, and an InGaAs/InAlAs high electron mobility transistor grown on an InP (001) substrate. Dynamical x-ray diffraction simulations were carried out in the 004, 115,135, and 117 geometry, assuming Cu kα
1
incident radiation, for both structures. The dislocation density strongly affects the intensities and widths of Pendellösung fringes, and we have established quantitative relationships which will allow characterization of the dislocation density.