Diffusion of Water Molecules in Amorphous Silica

作者：Kostinski Sarah^*; Pandey Ravindra; Gowtham S; Pernisz Udo; Kostinski Alexander

来源：IEEE Electron Device Letters, 2012, 33(6): 863-865.

DOI：10.1109/LED.2012.2189750

• Amorphous silica (a-SiO2)
• diffusion
• thin film
• water vapor

The diffusive penetration of atmospheric water vapor into amorphous silica (a-SiO2) degrades the performance of electronic devices. In this letter, we calculate the range of activation energies for water diffusion in a-SiO2 such that the diffusion time through, for example, a 0.5-mu m protective layer is on the order of the decadal time scale, as required in typical applications. We find that for all practical purposes, silica composed of n-member rings is impenetrable to water vapor for n %26lt;= 5. Thus, we conclude that the distribution of n-member rings in a-SiO2 and, specifically, the n %26gt; 5 fraction is the critical parameter for predicting device performance.

• 出版日期2012-6