The displacement field in highly non uniformly strained crystals is obtained by addition of constraints to an iterative phase retrieval algorithm. These constraints include direct space density uniformity and also constraints to the sign and derivatives of the different components of the displacement field. This algorithm is applied to an experimental reciprocal space map measured using high resolution X-ray diffraction from an array of silicon lines and the obtained component of the displacement field is in very good agreement with the one calculated using a finite element model.

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International audienceSymmetric and asymmetric reciprocal space maps (RSMs) of silicon on insulator (SOI) lines are obtained using high resolution x-ray diffraction. RSMs calculated from the displacement field simulated using finite element calculations show a good agreement with the experimental RSMs. These calculations indicate the large influence of the displacement field created by the silicon nitride cap and the sensitivity of the RSMs to the gradients of displacement at the edge of the SOI lines. They further show that the RSMs are influenced by local strains but also by local rotations of the crystal lattice connected with the strain distribution