Diffusion of iron in silicon dioxide

• Published in: Journal of the Electrochemical Society Vol. 146; no. 10; pp. 3773 - 3777
• Main Authors: RAMAPPA, D. A, HENLEY, W. B
• Format: Journal Article
• Language: English
• Published: Pennington, NJ Electrochemical Society 01.10.1999
• Subjects: Condensed matter: structure, mechanical and thermal properties; Diffusion in solids; Diffusion of impurities; Exact sciences and technology; Physics; Transport properties of condensed matter (nonelectronic); Impurity distribution; Photovoltaic effects; Temperature dependence; Segregation; X ray fluorescence; DLTS; Experimental study; Impurities; Silicon oxides; Arrhenius equation; Impurity diffusion; Iron additions; Total reflection; Diffusion; Activation energy
• ISSN: 0013-4651; 1945-7111
• DOI: 10.1149/1.1392548

A quantitative analysis of diffusion of iron in silicon dioxide is presented. A source of iron deposited on the surface of thermally oxidized silicon wafers was diffused at temperatures ranging from 700-1100 deg C in an inert (nitrogen) ambient. The iron concentration in SiO sub 2 and Si was measured using total reflection X-ray fluorescence, deep level transient spectroscopy, and surface photo-voltage techniques. A two-boundary diffusion model was applied to the experimental data to determine the diffusivity and segregation coefficient of iron in SiO sub 2 . It is observed that iron diffusivity in SiO sub 2 follows the Arrhenius relationship and has a thermal activation energy of 1.51 eV. Iron exhibits a strong tendency to segregate into silicon dioxide and has a value of k = 1.1 x 10 exp -7 at 1000 deg C, where k = N sub Si /N sub oxide .