Onefold coordinated oxygen atom: an electron trap in the silicon oxide

It has been long suggested that the SiOH defect is an electron or “water” trap in silicon dioxide based on some indirect evidences. In this work, quantum calculation on the capturing properties of non-bridging oxygen hole center with unpaired electron SiO^√ and hydrogen defect SiOH in silicon oxide are performed with the ab initio density-functional method. It was found that the SiO^√ defect is an electron trap and this defect should be the responsible candidate for better hardness against radiation for the metal–oxide-semiconductor gate oxide produced by wet oxidation. We found that the SiOH defect could not be an electron trap according to the present calculation results.