X-Ray Diffraction on Laser Disturbed Near-Surface Crystal Layers

Abstract

On the basis of statistical dynamic theory experimental results are analyzed of X-ray double-crystal diffraction from laser disturbed near-surface monocrystal Si layers induced by millisecond impulse irradiation. These investigations are carried out on silicon monocrystals (reflections (1 1 l), CuK,,irradiation) on the basis of double-crystal undispersed scheme (n, -n). The disturbance of the near-surface layer is caused by multiple laser irradiation. Numerical calculations are made for the model of a disturbed layer with a constant lattice deformation gradient and randomly stress deformations of statistically disturbed microdefects with variation of static Debye-Waller factor, correlation length, maximum lattice deformation, and disturbed layer thickness. Ha OCHOBe CTaTUCTUWCKOE nHHaMII%CKO% TeOpUIl aHaJIII3HpyIoTCR 3KCnePkiMeHTaJIbHbIe pe3yJIbTaTbI AByXKpHCTaJIbHO% PeHTreHOBCKO% AH@PaKTOMCTPMH H a HapyUIeHHbIX JIa3epHbIM MHJIJIHCeKyHAHbIM HMIIYJIbCHbIM H3JIyYeHIIeM npUIIOBepXHOCTHHbIX CJIORX MOHOKpIICTaJInOB KpeMHHR. 3KCIIepHMeH-TmbHbIe IlCCJIenOBaHHR IIpOBOnHJIHCb H a MOHOKPHCTaJIJIaX KpeMHHR (OTpaXeHIIe (1

The effect of ion implantation on structural damage of сompositionally graded AlGaN layers

“…To simulate X-ray diffraction spectra, we use the statistical dynamical theory of X-ray diffraction developed in Refs. [11][12][13] for uniform epitaxial films with randomly distributed microdefects. The coherent part of the diffracted intensity from a uniform crystalline layer is based on solution of the equations for the coherent and diffuse waves [11] under the condition 0 = u (where u is the statistical average of the displacement of the atoms from their positions in a perfect lattice [11,13,14]).…”

“…Reduction of diffracted intensity due to displacement fields u associated with microdefects is accounted by using the static Debye-Waller factor E [11,13,14]:…”

“…where ( ) ς g is the correlation function [11,13,16]. In general, there are few types of sphericalsymmetric microdefects, each requiring unique expressions for the correlation functions [13,14,16]. In this work, for the sake of simplicity the correlation function was generalized by the Gaussian function [13,16]:…”

“…Finally, within the kinematical approximation, the diffuse part of the diffracted intensity is given by [13,15]:…”

Untitled

“…Experimental verifications of SDT, using integrated reflectivities measurements have been discussed by Takama and Harima [2]. It has also been applied to diffraction by crystals with a perturbed surface layer [3,4], by crystals with a macroscopic deformation together with statistically distributed microdefects [5] and by multilayers systems [6,7].…”