Local strain induced in silicon by Si3N4 lines: Modeling and experimental investigation via X-ray diffraction

The influence of local strain fields on electrical properties such as the mobility of electrons and holes in silicon is of growing concern. In this work, we consider the displacement field generated in a semi-infinite Si substrate by a periodic array of lines located at the surface. We focus on a model system: an array of silicon nitride lines deposited on a monocrystalline silicon substrate. Measurements with X-ray diffraction (XRD) need mechanical modeling to validate the strain field. For that purpose we use finite element modeling (FEM) for simulating the displacement field, which is then used for calculating the diffracted intensity in the kinematical approximation. Agreement between measured and calculated intensity allows for a validation of the calculated strain field in the silicon.