Effects of Si-Layer-Thickness Ratio on UV-Light-Emission Intensity from Si/SiO₂ Multilayered Thin Films Prepared Using Radio-Frequency Sputtering

Kenta Miura^*, Hitomi Hoshino, Masashi Honmi, Osamu Hanaizumi

Graduate School of Science and Technology, Gunma University, Kiryu, Japan.

DOI: 10.4236/msa.2015.63025                

Abstract

We investigated the effects of Si-layer-thickness ratios on ultraviolet (UV) peak intensities of Si/ SiO₂ multilayered films produced by alternately stacking several-nanometer-thick Si and SiO₂ layers using radio-frequency sputtering for the first time. The Si-layer-thickness ratio of the Si/SiO₂ film is a very important parameter for enhancing the peak intensity because the ratio is concerned with the size of Si nanocrystals in the film, which might affect the intensity of the UV light emission from the film. We prepared seven samples with various estimated Si-layer-thickness ratios, and measured the photoluminescence spectra of the samples after annealing at 1150°C, 1200°C, or 1250°C for 25 min. From our experiments, we estimate that the proper Si-layer-thickness ratio to obtain the strongest UV peaks from the Si/SiO₂ multilayered films is around 0.29. Such a UV-lightemitting thin film is expected to be used in future higher-density optical-disk systems.

Keywords

Si, SiO₂, Multilayer, Sputtering, UV-Light Emission

Conflicts of Interest

The authors declare no conflicts of interest.

References

[1]	Koshida, N. and Koyama, H. (1992) Visible Electroluminescence from Porous Silicon. Applied Physics Letters, 60, 347- 349. http://dx.doi.org/10.1063/1.106652
[2]	Nakamura, T., Ogawa, T., Hosoya, N. and Adachi, S. (2010) Effects of Thermal Oxidation on the Photoluminescence Properties of Porous Silicon. Journal of Luminescence, 130, 682-687. http://dx.doi.org/10.1016/j.jlumin.2009.11.018
[3]	Pavesi, L., Negro, L.D., Mazzoleni, C., Franzo, G. and Priolo, F. (2000) Optical Gain in Silicon Nanocrystals. Nature, 408, 440-444. http://dx.doi.org/10.1038/35044012
[4]	Miura, K., Tanemura, T., Hanaizumi, O., Yamamoto, S., Takano, K., Sugimoto, M. and Yoshikawa, M. (2007) Fabri- cation of Blue-Light Emission Fused-Silica Substrates by Using Si ion Implantation and High-Temperature Annealing. Nuclear Instruments and Methods in Physics Research Section B, 263, 532-534. http://dx.doi.org/10.1038/35044012
[5]	Nakamura, T., Adachi, S., Fujii, M., Miura, K. and Yamamoto, S. (2012) Phosphorus and Boron Codoping of Silicon Nanocrystals by Ion Implantation: Photoluminescence Properties. Physical Review B, 85, Article ID: 045441. http://dx.doi.org/10.1103/PhysRevB.85.045441
[6]	Yamada, Y., Orii, T., Umezu, I., Takeyama, S. and Yoshida, T. (1996) Optical Properties of Silicon Nanocrystallites Prepared by Excimer Laser Ablation in Inert Gas. Japanese Journal of Applied Physics, 35, 1361-1365. http://dx.doi.org/10.1143/JJAP.35.1361
[7]	Song, H.Z., Bao, X.M., Li, N.S. and Wu, X.L. (1998) Strong Ultraviolet Photoluminescence from Silicon Oxide Films Prepared by Magnetron Sputtering. Applied Physics Letters, 72, 356-358. http://dx.doi.org/10.1063/1.120735
[8]	Miura, K., Kato, Y., Hoshino, H. and Hanaizumi, O. (2008) Fabrication of Ultraviolet-Light Emitting Si/SiO2 Multi- layered Films Using Radio-Frequency Magnetron Sputtering and High-Temperature Annealing. Thin Solid Films, 516, 7732-7734. http://dx.doi.org/10.1016/j.tsf.2008.04.057
[9]	Hanaizumi, O., Miura, K., Saito, M., Sato, T., Kawakami, S., Kuramochi, E. and Oku, S. (2000) Frontiers Related with Automatic Shaping of Photonic Crystals. IEICE Transactions on Electronics, E83-C, 912-919.
[10]	Kawakami, S., Sato, T., Miura, K., Ohtera, Y., Kawashima, T. and Ohkubo, H. (2003) 3D Photonic Crystal Heterostructures: Fabrication and In-Line Resonator. IEEE Photonics Technology Letters, 15, 816-818. http://dx.doi.org/10.1109/LPT.2003.811334
[11]	Kawashima, T., Sasaki, Y., Miura, K., Hashimoto, N., Baba, A., Ohkubo, H., Ohtera, Y., Sato, T., Ishikawa, W., Aoyama, T. and Kawakami, S. (2004) Development of Autocloned Photonic Crystal Devices. IEICE Transactions on Electronics, E87-C, 283-290.