We develop a general theory of crystal truncation rod (CTR) scattering from vicinal surfaces with a coherently strained heteroepitaxial film. The formalism incorporates film-induced interference fringes, full elastic lattice distortion, terrace ordering, surface reconstruction, and real-time growth evolution within a unified description. Comparison between the Nagai model and the elasticity-based model shows that the lattice tilt is nearly identical in the two approaches, whereas the elasticity-based model predicts an additional triclinic deformation arising from shear strain. This deformation has little effect on specular CTRs but strongly modifies nonspecular rods, making them a sensitive probe of the full elastic state of coherent epitaxial films. We further show that the characteristic sensitivity of vicinal CTRs to terrace ordering, surface reconstruction, and terrace-resolved compositional modification remains robust in the presence of a coherent film. Representative calculations for InGaN/GaN demonstrate that the framework enables quantitative interpretation of both static and real-time CTR measurements and provides access to step- and terrace-resolved structural and kinetic information during heteroepitaxial growth.

Close

PrevNext

View figure in article

• Epitaxial strain
• III-V semiconductors
• Surface growth
• Thin films
• Surface scattering
• X-ray diffraction
• X-ray scattering