Characterization of the porosity of silicon nitride thin layers by Electrochemical Impedance Spectroscopy

Thomas Barrès (1) , Bernard Tribollet (2) , O. Stephan (3) , H. Montigaud (1) , M. Boinet (4) , Y. Cohin (5)

1 SVI - Surface du Verre et Interfaces
2 LISE - Laboratoire Interfaces et Systèmes Electrochimiques
3 LPS - Laboratoire de Physique des Solides
4 Saint-Gobain Northboro Research and Development Center, Saint-Gobain Northboro Research and Development Center
5 SGR - Saint-Gobain Recherche

Silicon nitride thin films are widely used as diffusion barriers within stacks in the glass industry but turn out to be porous at the nanometric scale. EIS measurements were conducted on SiNx thin layers deposited on a gold layer. An electrochemical model was established to fit the EIS measurementsmaking use of data from other complementary techniques. In particular, Transmission Electron Microscopy was performed on these thin layers to determine the diameter and the qualitative morphology of the pores. A quantitative determination of the through-porosity of the layer was deduced from the EIS model and was in good agreement with TEM measurements. Moreover, combining EIS with local observations enabled inhomogeneitiesin the layer to be probed by highlighting a specific region in the layer.

Mots clés: Electrochemical Impedance Spectroscopy; Transmission Electron Microscopy; Porosity; Silicon Nitride; Thin Layer

Domaines: Science des matériaux [cond-mat.mtrl-sci]; Chimie

Thomas Barrès, Bernard Tribollet, O. Stephan, H. Montigaud, M. Boinet, et al.. Characterization of the porosity of silicon nitride thin layers by Electrochemical Impedance Spectroscopy. Electrochimica Acta, 2017, 227, pp.1 - 6. ⟨10.1016/j.electacta.2017.01.008⟩. ⟨hal-01452732⟩