Fabrication of Smooth Surface on 4H-SiC Substrate by Ultraviolet Assisted Local Polishing in Hydrogen Peroxide Solution


Article Preview

In this study, we investigated the possibility of removing and smoothing a single-crystal silicon carbide (SiC) surface under ultraviolet (UV) irradiation in hydrogen peroxide (H2O2) solution. In this method, a SiC substrate was excited by UV irradiation that transmitted synthetic quartz, and then an oxide layer on the SiC substrate was formed by photochemical reaction. Simultaneously, hydroxyl radical (OH*) was generated by the decomposition of H2O2 solution by UV irradiation. OH* plays an important role of oxidation of SiC surface. With these chemical reactions, oxide layer was effectively formed on the SiC surface. Finally, the oxide layer generated on a SiC substrate was chemically and/or mechanically removed by synthetic quartz and solutions. The polishing characteristics of this method were investigated by controlling the process parameters. Additionally, surface quality and removal depth were measured and evaluated by a phase-shift interference microscopy. Obtained results show that the surface morphology and the removal rate are strongly dependent on the existence of the UV irradiation. Moreover, it is shown that the removal characteristics of the SiC substrate depend on the process parameters such as the process time, reciprocating speed, and contact load. The processed surface has revealed that many scratches on the preprocessed surface was completely removed. The microroughness of the processed surface was improved to 0.15 nm (Rms) and 1.62 nm (p-v), respectively. These results provide useful information for obtaining an atomically smooth SiC surface.



Key Engineering Materials (Volumes 523-524)

Edited by:

Tojiro Aoyama, Hideki Aoyama, Atsushi Matsubara, Hayato Yoshioka and Libo Zhou




A. Kubota et al., "Fabrication of Smooth Surface on 4H-SiC Substrate by Ultraviolet Assisted Local Polishing in Hydrogen Peroxide Solution", Key Engineering Materials, Vols. 523-524, pp. 24-28, 2012

Online since:

November 2012




[1] L. Zhou, V. Audurier, P. Pirouz and J. A Powell, Chemomechanical polishing of silicon carbide, J. Electrochem. Soc. 144 (1997) L161-L163.

DOI: https://doi.org/10.1149/1.1837711

[2] F. Owman, C. Hallin, P. Martensson and E. Janzen, Removal of polishing-induced damage from 6H-SiC(0001) substrates by hydrogen etching, J. Cryst. Growth. 167 (1996) 391-395.

DOI: https://doi.org/10.1016/0022-0248(96)00296-5

[3] V. Ramachandran, M. F. Brady, A. R. Smith, R. M. Feenstra, and D. W. Greve, Preparation of atomically flat surfaces on silicon carbide using hydrogen etching, J. Electron. Mater. 27 (1998) 308-312.

DOI: https://doi.org/10.1007/s11664-998-0406-7

[4] B. Kim, H. J. Choi and B. T. Lee, Surface roughness of silicon carbide etched in a C2F6/O2 inductively coupled plasma, J. Vac. Sci. Technol. A 20 (2002) 424-429.

DOI: https://doi.org/10.1116/1.1448509

[5] H. Hara, Y. Sano, H. Mimura, K. Arima, A. Kubota, K. Yagi and K. Yamauchi, Novel abrasive-free planarization of 4H-SiC (0001) using catalyst, J. Electron. Mater. 35 (2006) L11-L14.

DOI: https://doi.org/10.1007/s11664-006-0218-6

[6] K. Yamamura, T. Takiguchi, M. Ueda, H. Deng, A.N. Hattori, N. Zettsu, Plasma assisted polishing of single crystal SiC for obtaining atomically flat strain-free surface, CIRP Annals - Manufacturing Technology 60 (2011) 571-574.

DOI: https://doi.org/10.1016/j.cirp.2011.03.072

[7] S.H. Hong, J. Watanabe, M. Touge, Precision polishing technology of SiC single crystal under Ultraviolet-ray irradiation, Int. J. for Manufacturing Science & Technology 9 (2007) 23–28.

[8] J. Watanabe, S.H. Hong, K. Yamaguchi, M. Touge, N. Kuroda, Effect of TiO2 and CeO2 Particles on SiC semiconductor surfaces polished under Ultraviolet-ray irradiation, Proc. Advances in Abrasive Technology (ASAAT 2007), Michigan, USA (2007) 91–96.

[9] J. S. Shor and A. D. Kurtz, Photoelectrochemical etching of 6H-SiC, J. Electrochem. Soc. 141 (1994) 778-781.

DOI: https://doi.org/10.1149/1.2054810

[10] Y. Ishikawa, Y. Matsumoto, Y. Nishida, S. Taniguchi, and J. Watanabe, Surface Treatment of Silicon Carbide Using TiO2(IV) Photocatalyst, J. Am. Chem. Soc. 125 (2003) 6558–6562.

DOI: https://doi.org/10.1021/ja020359i