[25p-P05-1~2] 13.3 Insulator technology

[25p-P05-2] Dependence of activation energy for mobility of ions in Si₃N₄ and SiO₂ films on ion radius

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

Keywords:humidity resistance, ion contamination, molecular orbital calculation

The formation energy delta H_d during the permeation of monovalent and divalent ions in the SiN_x and SiO_x films was calculated by the semi-empirical molecular orbital method. The results did not agree with the expectation that the larger the ionic radius, the more difficult it is to enter the membrane. Assuming that delta H_d is equal to mesh deformation and electrostatic interaction, it can be explained that delta H_d is smaller for divalent ions than for monovalent ions, but it cannot be explained that delta H_d for Cs ⁺, Sr^{2 +}, and Ba^{2 +} is smaller. The calculation results show that the charges of these ions are smaller than +1 and +2, which is considered to be the reason why delta H_d is small.