Measuring interface strains at the atomic resolution in depth using x-ray Bragg-surface diffraction

Abstract

A generic x-ray diffraction method, using three-wave Bragg-surface diffraction, is developed to measure strains at the interface of molecular beam epitaxial Au∕GaAs(001), where grazing-incidence diffraction cannot be applied due to the difference in refractive index between Au and GaAs. Changes in diffraction images of the surface reflection (1−13) of GaAs(006)∕(1−13) three-wave Bragg-surface diffraction and the (−1−13) of GaAs(006)∕(−1−13) at different azimuth and Bragg angles give the depth penetration of 2Å resolution and variations of lattice constant, −49%, −27%, and 2%, along the surface normal [001] and in-plane directions [−1−10] and [1−10] within the depths of 18, 72, and 72Å, respectively.