Abstract
The anodic dissolution ofp-Si in fluoride media has been studied, usingin-situ infrared spectroscopy, for various compositions of the electrolyte (fluoride concentration andpH). The interfacial layer present in the electropolishing regime has been investigated as a function of potential. At potentialsE<1–2V SCE, this layer mainly consists of a wet oxide or hydroxide. A well-defined oxide appears only aboveE∼2V SCE, beyond a second current maximum. The thickness of the oxide layer is in the range 0–100Å, and increases with increasing potential. The infrared spectra of the oxide layer reveal a minimum structural disorder of the oxide in the mid-region of the second current plateau. The potential range of this optimum oxide perfection increases when going to electrolytes giving rise to lower current densities. Incorporation of ions from the electrolyte may occur in the low-potential range. Potential-modulated infrared spectroscopy reveals a large accumulation of holes forE>2V SCE. This indicates that, in this potential range, the limiting step for anodic current flowing is the availability of sites for hole transfer into the oxide layer. On the other hand, the weak hole accumulation which is observed forE<2V SCE indicates a large density of hole-acceptor sites in the wet oxide layer. Finally, the current oscillations observed in the far anodic region (E>3V SCE) are found to be associated with an oscillation of the oxide thickness, which may reach an amplitude of the order of 30Å.
References
Ashley K and Pons S 1988Chem. Rev. 88 673
Bensch W and Bergholz W 1990Semicond. Sci. Technol. 5 421
Boyd I W and Wilson J I B 1982J. Appl. Phys. 53 4166
Chabal Y J 1988Surf. Sci. Rep. 8 211
Chazalviel J N 1992Electrochim. Acta 37 865
Chazalviel J N, Etman M and Ozanam F 1991J. Electroanal. Chem. 297 533
Chazalviel J N, Mandal K C and Ozanam F 1992SPIE Proc. 1575 40
Hassan H H, Chazalviel J N, Etman M, Neumann-Spallart M and Ozanam F 19932nd Int. Conf. on Solar Energy Storage and Applied Photochemistry, Cairo, Egypt, abstract, p. 46
Kirk C T 1988Phys. Rev. B38 1255
Lange P, Schnakenberg Ullerich S and Schliwinski H J 1990J. Appl. Phys. 68 3532
Lewerenz H J and Aggour M 1993J. Electroanal. Chem. 351 159
Mishima Y, Hirose M, Osaka Y and Ashida Y 1984J. Appl. Phys. 55 1234
Ozanam F, Blanchard N and Chazalviel J N 1993Electrochem. Acta 38 1627
Ozanam F and Chazalviel J N 1993J. Electron. Spectrosc. 64/65 395
Ozanam F, Chazalviel J N, Radi A and Etman M 1992J. Electrochem. Soc. 139 2491
Pai P G, Chao S S, Takagi Y and Lucovsky G 1986J. Vac. Sci. Technol. A4 689
Ramkumar K and Saxena A N 1992J. Electrochem. Soc. 139 1437
Stumper J, Greef R and Peter L M 1991J. Electroanal. Chem. 310 445
Theil J A, Tsu D V, Watkins M W, Kim S S and Lucovsky G 1990J. Vac. Sci. Technol. A8 1374
Author information
Authors and Affiliations
Rights and permissions
About this article
Cite this article
Ozanam, F., da Fonseca, C. & Chazalviel, J.N. In-situ infrared study of the interfacial layer during the anodic dissolution of a silicon electrode in a fluoride electrolyte. Proc. Indian Acad. Sci. (Chem. Sci.) 107, 709–719 (1995). https://doi.org/10.1007/BF02869962
Issue Date:
DOI: https://doi.org/10.1007/BF02869962