Premium
The SiO 2 ‐SI 3 N 4 Interface, Part II: O 2 Permeation and Oxidation Reaction
Author(s) -
Ogbuji Linus U. J. T.
Publication year - 1995
Publication title -
journal of the american ceramic society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.9
H-Index - 196
eISSN - 1551-2916
pISSN - 0002-7820
DOI - 10.1111/j.1151-2916.1995.tb08482.x
Subject(s) - suboxide , permeation , oxide , diffusion , chemistry , silicon , thermodynamics , materials science , chemical engineering , metallurgy , biochemistry , physics , membrane , engineering
Previous analyses of Si 3 N 4 oxidation on the basis of diffusion control by a suboxide layer yielded impossibly high N 2 pressures. Those models assumed interfacial reactions as the oxidation mechanism. However, it is now thought that the oxidation process is in situ substitution of O for N in silicon oxynitride of graded composition rather than interfacial reaction. In this paper, diffusional and thermodynamic analyses appropriate to this mode of oxidation are developed for both the permeation and reaction aspects of oxidation; O 2 diffusivities are calculated from permeation energies; gas pressures in the oxide are derived from solution thermodynamics and found to be moderate.