| AVS 60th International Symposium and Exhibition | |
| Electronic Materials and Processing | Wednesday Sessions |
| Session EM+AS+NS+SS-WeA |
| Session: | Semiconductor Heterostructures/Heusler Alloys |
| Presenter: | P.B. Rago, University of Connecticut |
| Authors: | P.B. Rago, University of Connecticut J.E. Ayers, University of Connecticut |
| Correspondent: | Click to Email |
In previous work an approximate phase invariant dynamical diffraction model (PIDDM) has been developed for the analysis of high-resolution x-ray rocking curves from metamorphic semiconductor heterostructures containing threading dislocations. In principle, use of the PIDDM allows depth profiling of composition, strain, and dislocation density in device structures. It accounts for the broadening of diffraction linewidths through the use of an effective deviation parameter, which includes the angular mosaic spread and lattice spacing mosaic spread of a crystal distorted by dislocations. Although the PIDDM correctly predicts the linewidth broadening of diffraction profiles, it is unable to account for some features of the rocking curves from metamorphic structures, such as the suppression of the Pendellosung fringes and the extinction behavior of layers with high dislocation densities. To address these issues, we have developed a refined model for dynamical diffraction from dislocated semiconductor heterostructures, the Mosaic Crystal Dynamical Diffraction Model (MCDDM), which includes phase variations between blocks of the mosaic crystal. In this paper, we compare the PIDDM and MCDDM for the case of metamorphic InGaAs/GaAs (001) heterostructures, and illustrate the situations in which the more complex MCDDM needs to be applied.