[20a-PA5-1~14] 13.3 Insulator technology

[20a-PA5-1] Penetration of H₂O molecule into SiO₂ films with a variety of crystal structure

〇Tomoki Oku¹, Masahiro Totsuka¹, Hajime Sasaki¹ (1.Mitsubishi Electric Corporation)

Keywords:silicon oxide, moisture resistance, molecular orbital calculation

We simulated the penetration of a H₂O molecule into the SiO₂ crystals (high temperature type cristobalite, high temperature type tridymite, high temperature type quartz) by a semi-empirical molecular orbital calculation method and evaluated the diffusion barrier and the penetration barrier. As a result, we found that the barrier depends on both the crystal structure and the plane orientation. The dependence indicates that moisture resistance of SiO₂ crystals can be improved by optimizing the crystal structure and the surface orientation.