Atomic and electron analyzing of irradiation damage in Si/SiO2 interfaces caused by irradiation: First-principle calculation

Abstract α-SiO 2 /Si interfaces are easy to suffer from ionization irradiation damage, leading to the formation of interface traps, whose mechanisms are very complicated and not clear so far. In this paper, four types of interfaces are constructed in order to study the irradiation damage on Si/SiO 2 interfaces aiming to investigate interfaces under positive and neutral states. From atomic structures, interfaces with oxygen (I(I)) move less than ones with dangling bonds (I(II)) and ones with hydrogen atoms (I(III)), and bonds between hydrogen and Silicon break forming hydrogen ions when interfaces with hydrogen in positive charged states (I(IV)) change from neutrality to positivity. By electron transfer distribution, oxygen in I(I) can effectively form bond with silicon reducing dangling bonds, while I(III) and I(II) exist some. I(I) has less interface traps than I(III) and I(II), and I(IV) can reduce interface traps by density of states. Band offsets of I(I) is the highest leading to least leakage current, while I(III) and I(II) has lower band offsets. For interfaces fulling with hydrogen atoms, different charged states cannot effect band offsets enormously. As for I(I) and I(II) calculated by nonequilibrium Boltzmann, the leakage current increase with temperature increasing, while that of I(III) decreases. The simulation can be useful to explain the degeneration and damage mechanisms.