[18p-PB2-1~4] 13.3 Insulator technology

[18p-PB2-1] Orientation dependence of the penetration barrier of H₂O molecule into SiO₂ and Si₃N₄ films

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

Keywords:humid resistivity, crystal direction, molecular orbital calculation

In the previous report, a molecular orbital calculation showed that the humid resistivities of the SiO₂ crystals are explained by the gap size in cristobalite, tridymite, quartz and coesite and are lesser than that of the Si₃N₄ crystal. In this report, we show the penetration barrier of the Si₃N₄ to the direction of [1000] could be higher than that of [0001]. However, the penetration barrier of the Si₃N₄ is considered to be maintained at high energy only within the a few atomic layers, because the H₂O molecule changes the direction from [1000] to [0001] at the third layer from the Si₃N₄ crystal surface.