Near interface oxide degradation in high temperature annealed Si /SiO2/Si structures

摘要

Degradation of 430 nm thick SiO(sub 2) layers in Si/SiO(sub 2)/Si structures which results from high temperature annealing (1320 C) has been studied using electron spin resonance, infra-red and refractive index measurements. Large numbers of oxygen vacancies are found in a region (= or <)100 nm from each Si/SiO(sub 2) interface. Two types of paramagnetic defects are observed following (gamma) or x-irradiation or hole injection. The 1106 cm(sup (minus)1) infra-red absorption associated with O interstitials in the Si substrate is found to increase with annealing time. The infra-red and spin resonance observations can be explained qualitatively and quantitatively in terms of a model in which oxygen atoms are gettered from the oxide into the under or overlying Si, the driving force being the increased O solubility limit associated with the anneal temperature.