Estimation of breakdown electric-field strength while reflecting local structures of SiO ₂ gate dielectrics using first-principles molecular orbital calculation technique

To achieve metal-oxide-semiconductor field-effect transistors (MOSFETs) with high reliability, it is important to investigate the dielectric breakdown of gate oxide films of MOSFETs. It is known that dielectric breakdown is usually due to the presence of defects in films. Estimating the breakdown electric-field strength while reflecting local structures such as defects is important for investigation of the reliability of gate SiO ₂ films. In this study, we introduce the "recovery rate", which is a parameter potentially capable of estimating the breakdown electric-field strength while reflecting the local structures of the film. The recovery rate has a strong correlation with the breakdown electric-field strength of bulk Si and Al compounds. Using this correlation, we estimate the breakdown electric-field strength of SiO ₂ with oxygen vacancies and strains.