Nanowires fine tunable fabrication by varying the concentration ratios, the etchant and the plating spices in metal-assisted chemical etching of silicon wafer.


1 Semiconductors, Materials and Energy Research Center (MERC)

2 Semiconductors , Materials and Energy Research Center (MERC)

3 Nano-Technology and Advanced Materials, Materials and Energy Research Center


The metal-assisted chemical etching (MACE) was used to synthesis silicon nanowires. The effect of etchant concentration, etching and chemical plating time and doping density on silicon nanowires length were investigated. It is held that the increasing of HF and H2O2 concentrations lead to etching rate increment and formation of wire-like structure. The results show that, the appropriate ratio of concentration to form the silicon nanowires obeyed the [HF]/[H2O2]  = R equation when R= 2.5, 3 and 3.5 and any deviation of these ratio, cause to destruction of wire-like structure. Moreover, the critical etching rates to form the SiNWs are in the range of 4nm/s to 5nm/ s.


1. Li, Z., Chen, Y., Li, X., Kamins, T.I., Nauka, K. and Williams, R.S., "Sequence-specific label-free DNA sensors based on silicon nanowires", Nano Letters, Vol. 4, No. 2, (2004), 245- 247.

2. Kelzenberg, M.D., Turner-Evans, D.B., Kayes, B.M., Filler, M.A., Putnam, M.C., Lewis, N.S. andAtwater, H.A., "Photovoltaic measurements in single-nanowire silicon solar cells", Nano letters, Vol. 8, No. 2, (2008), 710-714.

3. Wu, H. and Cui, Y., "Designing nanostructured Si anodes for high energy lithium ion batteries", Nano Today, Vol. 7, No. 5, (2012), 414-429.

4. Massoudi, A., Azim-Araghi, M. and Asl, M.K., " Fabrication of p-Type Nano-porous Silicon Prepared by Electrochemical Etching Technique in HF-Ethanol and HF-Ethanol-H2O Solutions", Advanced Ceramics Progress, Vol. 1, No. 2, (2015), 24-28

5. Su, X., Wu, Q., Li, J., Xiao, X., Lott, A., Lu, W., Sheldon, B.W. and Wu, J., "Silicon-based nanomaterials for lithium-ion batteries: a review", Advanced Energy Materials, Vol. 4, No. 1, (2014), 1-7.

6. Tian, B., Zheng, X., Kempa, T.J., Fang, Y., Yu, N., Yu, G., Huang, J. and Lieber, C.M., "Coaxial silicon nanowires as solar cells and nanoelectronic power sources", Nature, Vol. 449, (2007), 885-889.

7. Chan, C.K., Peng, H., Liu, G., McIlwrath, K., Zhang, X.F., Huggins , R.A. and Cui, Y., "High-performance lithium battery anodes using silicon nanowires", Nature Nanotechnology, Vol. 3, No. 1, (2008), 31-35.

8. Hochbaum, A.I., Chen, R., Delgado, R.D., Liang, W., Garnett, E.C., Najarian, M., Majumdar, A. and Yang, P., "Enhanced thermoelectric performance of rough silicon nanowires", Nature, Vol. 451, (2008), 163-167.

9. Laer, R.V., Kuyken, B., Thourhout, D.V. and Baets, R., "Interaction between light and highly confined hypersound in a silicon photonic nanowire", Nature Photonics, Vol. 9, No. 3, (2015), 199-203.

10. Dubal, D.P., Aradilla, D., Bidan, G., Gentile, P., Schubert, T.J.S., Wimberg, J., Sadki, S. and Romero, P.G., "3D hierarchical assembly of ltrathin MnO2 nanoflakes on silicon nanowires for high performance micro-supercapacitors in Lidoped ionic liquid", Scientific Reports, Vol. 5, (2015), 9771.

11. Hochbaum, A.I., Fan, R., He, R. and Yang, P., "Controlled growth of Si nanowire arrays for device integration", Nano letters, Vol. 5, No. 3, (2005), 457-460.

12. Tang, Y.H, Zhang, Y.F., Wang, N., Lee, C.S., Han, X.D., Bello, I. and Lee, S.T., "Morphology of Si nanowires synthesized by high-temperature laser ablation", Journal of Applied Physics, Vol. 85, No. 11, (1999), 7981-7983.

13. Juhasz, R., Elfström, N. and Linnros, J., "Controlled fabrication of silicon nanowires by electron beam lithography and electrochemical size reduction", Nano letters, Vol. 5, No. 2, (2005), 275-280.

14. Han, H., Huang, Z. and Lee, W., "Metal-assisted chemical etching of silicon and nanotechnology applications", Nano Today, Vol. 9, No. 3, (2014), 271-304.

15. Geyer, N., et al., "Ag-mediated charge transport during metalassisted chemical etching of silicon nanowires" ACS Applied Materials & Interfaces, Vol. 5, No. 10, (2013), 4302-4308.

16. Zeis, R., Lei, T., Sieradzki, K., Snyder, J. and Erlebacher, J., "Catalytic reduction of oxygen and hydrogen peroxide by nanoporous gold", Journal of Catalysis, Vol. 253, No. 1, (2008), 132-138.

17. Hildreth, O., Rykaczewski, K. and Wong, C.P. "Participation of focused ion beam implanted gallium ions in metal-assisted chemical etching of silicon", Journal of Vacuum Science and Technology B:Nanotechnology and Microelectronics, Vol. 30, No. 4, (2012), 040603.

18. Yue, Z., Shen, H., Jiang , Y., Wang, W. and Jin, J., "Novel and low reflective silicon surface fabricated by Ni-assisted electroless etching and coated with atomic layer deposited Al2O3 film", Applied Physics A, Vol. 114, No. 3, (2014), 813-817.

19. Bai, F., Li, M., Song, D., Yu, H., Jiang, B. and Li, Y., "Onestep synthesis of lightly doped porous silicon nanowires in HF/AgNO3/H2O2 solution at room temperature", Journal of Solid State Chemistry, Vol. 196, (2012), 596-600.

20. Divan, R., Rosenthal, D., Karim Ogando, K., Ocola, L.E., Rosenmann, D. and Moldovan, N., "Metal-assisted etching of silicon molds for electroforming", Journal of Vacuum Science & Technology B, Nanotechnology and Microelectronics: Materials, Processing, Measurement, and Phenomena, Vol. 31, No. 6, (2013), 06FF03.

21. Chang, S.W., Chuang, V.P., Boles, S.T., Ross, C.A. and Thompson, C.V., "Densely packed arrays of ultra‐high‐aspectratio silicon nanowires fabricated using block‐copolymer lithography and metal‐assisted etching", Advanced Functional Materials, Vol. 19, No. 15, (2009), 2495-2500.

22. Peng, K., Hu, J.J., Yan, Y.J., Wu, Y., Fang, H., Xu, Y., Lee, S.T. and Zhu, J., "Fabrication of single‐crystalline silicon nanowires by cratching a silicon surface with catalytic metal particles", Advanced Functional Materials, Vol. 16, No. 3, (2006), 387-394.