Smoothing Mechanism of Reaction Sintered SiC in Plasma Assisted Polishing Using Ceria Abrasive

Abstract:

For the finishing of some difficult-to-machine materials, a novel polishing technique named plasma assisted polishing (PAP) was proposed. Ceria abrasive polishing with different electric power plasma irradiation was conducted on RS-SiC surface. Low RF power plasma (8 W) was used, many protrusions were generated which made the surface roughnesses bad (60.93 nm p-v, 5.51 nm rms). In contrast, the height and amount of protrusions decreased when RF power was increased to 12 W, which made the surface roughness better (31.83 nm p-v, 2.63 nm rms). Also, scratches completely disappeared after PAP. To explain the above results, the relationship of oxidation rate by plasma irradiation and material removal rate by abrasive polishing was taken into consideration. The different compositions in RS-SiC have different oxidation rates and levels of hardness. When the oxidation rate is higher than material removal rate, the heterogeneous polishing of RS-SiC is turned to homogeneous polishing of SiO₂, and then a flat surface with an oxide layer can be obtained. To prove the above assumption, we firstly oxidized the surface with plasma irradiation for 1 h, and then PAP with a much lower load was conducted on the oxidized surface for 0.5 h. A scratch-free surface with 12.61 nm p-v and 1.45 nm rms was obtained which coincides with the mechanism we propose.

• Periodical: Key Engineering Materials (Volume 516)
• Pages: 119-124
• DOI: https://doi.org/10.4028/www.scientific.net/KEM.516.119
• Online since: June 2012
• Authors: Hui Deng, Masaki Ueda, Kazuya Yamamura
• Keywords: Atmospheric Pressure Plasma, Oxidation, Polishing, Scratch-Free, Silicon Carbide (SiC)

References

[1] S. Suyama, Y. Itoh, Evaluation of microstructure of high-strength reaction sintered silicon carbide for optical mirror, Proc. of SPIE 6666 (2007) 66660K-1-11.

DOI: 10.1117/12.733832

[2] S. Suyama, T. Kameda, Y. Itoh, Development of high-strength reaction-sintered silicon carbide, Diamond Relat. Mater. 12 (2003) 1201-1204.

DOI: 10.1016/s0925-9635(03)00066-9

[3] H. Y. Tam, H. B. Cheng, Y. W. Wang, Removal rate and surface roughness in the lapping and polishing of RB-SiC optical components, J. Mater. Proc. Technol. 192-193 (2007) 276-280.

DOI: 10.1016/j.jmatprotec.2007.04.091

[4] J. W. Yan, Z. Y. Zhang, T. Kuriyagawa, Mechanism for material removal in diamond turning of reaction-bonded silicon carbide, Int. J. Mach. Tool. Manu. 49 (2009) 366-374.

DOI: 10.1016/j.ijmachtools.2008.12.007

[5] J. Q. Gao, J. Chen, G. L. Liu, Y. J. Yan, X. J. Liu, Z. R. Huang, Role of microstructure on surface and subsurface damages of sintered silicon carbide during grinding and polishing, Wear 270 (2010) 88-94.

DOI: 10.1016/j.wear.2010.09.009

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

DOI: 10.1149/1.1837711

[7] M. Kikuchi, Y. Takahashi, T. Suga, Mechanochemical polishing of silicon carbide single crystal with chromium (III) oxide abrasive, J. Am. Ceram. Soc. 75 (1992) 189-194.

DOI: 10.1111/j.1151-2916.1992.tb05463.x

[8] K. Yamamura, T. Takiguchi, M. Ueda, A. N. Hattori, N. Zettsu, High-integrity finishing of 4H-SiC (0001) by plasma-assisted polishing, Adv. Mater. Res. 126-128 (2010) 423-428.

DOI: 10.4028/www.scientific.net/amr.126-128.423

[9] H. Deng, T. Takiguchi, M. Ueda, A. N. Hattori, N. Zettsu, K. Yamamura, Damage-free dry polishing of 4H-SiC combined with atmospheric-pressure water vapor plasma oxidation, Jpn. J. Appl. Phys. 50 (2011) 08JG05-1-4.

DOI: 10.7567/jjap.50.08jg05

[10] 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, Ann. CIRP 60 (2011) 571-574.

DOI: 10.1016/j.cirp.2011.03.072

[11] B. Hornetz, H-J. Michel, J. Halbritter, ARXPS studies of SiO2-SiC interfaces of 6H-SiC single crystal Si-(001) and C-(00_1) surfaces, J. Mater. Res. 9 (1994) 3088-3094.

DOI: 10.1557/jmr.1994.3088

[12] Information on http: /srdata. nist. gov/xps.

[13] T. L. Barr, An ESCA study of the termination of the passivation of elemental metals, J. Phys. Chem. 82 (1978) 1801-1810.

DOI: 10.1021/j100505a006

[14] W. C. Oliver, G. M. Pharr, An improved technique for determining hardness and elastic modulus using load and displacement sensing indentation experiments, J. Mater. Res. 7 (1992) 1564-1583.

DOI: 10.1557/jmr.1992.1564