Raman spectroscopy study of damage and strain in (001) and (011) Si induced by hydrogen or helium implantation

摘要

We use Raman spectrometry to investigate lattice disorder and strain induced by hydrogen or helium implantation in (001) and (011) Si. The phonon peak intensities and the spatial correlation model are used to estimate the amount of damage affecting the phonon coherence length. The redshift due to reduced coherence length is taken into account to fit the model to the experimental spectra. This allows us to correctly estimate a blueshift attributed to a compressive in-plane strain. We observe that the amount of strain increases linearly with the implant dose. For H implants the dependence of strain on crystallographic orientation was discovered. This effect is attributed to the anisotropic morphology of the H-induced extended defects: two-dimensional platelets with preferred orientations versus spherical nanobubbles formed after He implants. Raman results are correlated with the implant damage simulations and compared with the data obtained by other characterization techniques.