Structural changes in Si crystals exposed to chemical etching and ion implantation

Results of X-ray diffraction studies on structural changes in Si crystals caused by chemical etching for 40 s in HF, HNO₃ solution and phosphorus-ion implantation with the energy E = 100 keV and dose D = 8 × 10¹⁴ cm⁻² are represented.

Two- and three-crystal X-ray diffractometry methods are used for a quantitative assessment of structural changes occurring in the near-surface crystal layers. Analysis of experimental rocking curves was made with the use of different approaches developed on the basis of kinematic and dynamic theory of X-ray scattering in the imperfect crystals. A model of possible system of structural defects in the near-surface silicon layers modified by chemical etching and ion implantation is proposed. The model accounts for the availability of respective sizes and concentrations of spherical and disc-shaped cluster formations, dislocation loops.