STUDY OF STRESS-RELAXATION IN IMPLANTED SILICON ON SAPPHIRE STRUCTURES USING RAMAN-SPECTROSCOPY

The article is focused on stress relaxation studies in silicon on sapphire structures resulting from post-implantation thermal annealings. Stress recovers for low dose irradiated materials but remains at a lower value for samples irradiated by high doses. A mechanism for the stress relaxation involves formation of vacancy-like complexes near the Si-Al2O3 interface which compensate stress. The complexes are created during post-implantation annealings owing to thermal activation. diffusion and accumulation of mobile vacancies from the disordered layer to the Si-Al2O3 boundary. The proposed model was successfully computer simulated using parameters appropriate for vacancy-stress interactions.