X-ray diffraction from low temperature ion implanted silicon

Abstract

Double-crystal X-ray diffraction rocking curves (RCs) have been measured at 77 K for silicon wafers implanted with 3 MeV Ni ions at 130 K. Rather symmetric broadening of RC of the sample implanted with 1 × 10 14 Ni 3+ /cm 2 was observed. It may be a kind of distortion scattering caused by vacancies, interstitials and their agglomerates. Modulated profile of the sample implanted with 4 × 10 14 Ni 3+ /cm 2 is a result of the nonuniform strain distribution. By further implantation, the modulating profile changes to a rather monotonous shape. It is considered to be a result of the strain fluctuation in an identical depth and the increasing of amorphous region reducing the coherency of X-rays. The annealing experiments were also carried out up to 1073 K. The change of RCs started even below room temperature and is rather continuous. It leads to the fact that the recovery of defects is rather continuous in temperatures. The recovery was completed at 1073 K. Numerical calculations for the depth profiles of the strain were carried out from the fitting of the simulated RCs to those observed.