The grazing incidence small angle X-ray scattering (SAXS) technique was used to study monocrystalline silicon samples implanted with H2 ions at energy of 32 keV and to the dose of 1E16 ions/cm2. Samples were annealed isochronally at different temperatures in the range from 100 to 900 C.
Although the H depth distribution was expected to be smooth initially, nanosized features, like agglomerates of defects have been detected (minor correlation peak observed in implanted but not annealed sample). Annealing destroys this feature due to the relaxation of defects strucutres, i.e. redistribution of vacancies and hydrogen. Above 300 C a well defined film with highly correlated borders is formed on the edge of the layer rich in defects, whose thickness is slowly decreasing from 17 to 12 nm with increasing annealing temperature. Moreover, defects as well as hydrogen are migrating towards the surface with increasing annealing temperature, as indicated by the increase in surface roughness. We will present a model for the film structure changes obtained by data evaluation based on the distorted wave Born approximation.