[8a-A411-1~10] 13.1 Fundamental properties, surface and interface, and simulations of Si related materials

[8a-A411-1] Atomic H Charge and Blueshift of H₂ Molecular Vibration in SiO₂/Si systems

〇Koichi Kato¹, Katsuyuki Fukutani¹ (1.Univ. Tokyo, IIS)

Keywords:hydrogen, reliability, degradation

Degradation of SiO2 by H atoms has strong influences on lifetimes of silicon devices. H molecules are also found to be condensed at the SiO2/Si interafces, and must be giving chemical influences on the devices. H2 molecular vibration shows redshift in silicon, but is found to show blueshift from the interface toward SiO2. Although the H atomic charges were evaluated to be negative throughout in the devices by Wigner-seitz cell, the effective charges are found to be almost positive from the interface toward SiO2 by accurate Born charges through Berry phase formalism.