Silicon carbide (SiC) is a next-generation semiconductor material. However, SiC is difficult to machine because it has high mechanical hardness and chemical inertness. Therefore, high-quality processing technology with high efficiency is now required. In our previous study, the authors developed UV-assisted grinding method and clarified that the critical depth of cut is expanded by UV irradiation and that the surface roughness is reduced by applying this method with a composite-abrasive wheel containing diamond abrasive grains with a mean abrasive diameter of 6 μm. On the other hand, it is important to reduce the damaged layer left by lapping or polishing process after grinding. In this study, we developed UV-assisted constant-pressure grinding method as a new alterative processing method to lapping and polishing. In this method, UV-assisted grinding is applied to the constant-pressure grinding method. To obtain a higher-quality mirror surface, we used a superabrasive wheel containing diamond abrasive grains with a mean abrasive diameter of 0.5 μm. By investigating the influence of UV irradiation on processing characteristics, we clarified that the surface roughness and removal height were reduced by UV irradiation. Finally, a high quality surface with few grinding marks was obtained by UV-assisted constant-pressure grinding.

1. [1] K. Yamamura, T. Takiguchi, M. Ueda, H. Deng, A. N. Hattori, and N. Zettsu, “High-integrity finishing of 4H-SiC (0001) by plasma-assisted polishing,” J. of the Japan Society for Abrasive Technology, Vol.55, No.9, pp. 534-539, 2011.
2. [2] H. Deng, S. Makiyama, and K. Yamamura, “Development of plazma-assisted polishing (4th report),” Proc. of JSPE Semestrial Meeting, pp. 764-765, 2011.
3. [3] H. Deng and K. Yamamura, “Development of plazma-assisted polishing (5th report),” Proc. of JSPE Semestrial Meeting, pp. 313-314, 2012.
4. [4] H. Deng and K. Yamamura, “Development of plazma-assisted polishing (6th report),” Proc. of JSPE Semestrial Meeting, pp. 965-966, 2013.
5. [5] H. Deng, K. Endo, and K. Yamamura, “Development of plazma-assisted polishing (7th report),” Proc. of JSPE Semestrial Meeting, pp. 219-220, 2013.
6. [6] H. Deng, K. Endo, and K. Yamamura, “Development of plazma-assisted polishing (9th report),” Proc. of JSPE Semestrial Meeting, pp. 635-636, 2014.
7. [7] C. Kageyama, K. Monna, T. Tabata, H. Deng, K. Endo, and K. Yamamura, “Development of plazma-assisted polishing (15th report),” Proc. of JSPE Semestrial Meeting, pp. 377-378, 2015.
8. [8] K. Tsujiuchi, S. Rongyan, Y. Ohkubo, K. Endo, and K. Yamamura, “Development of plazma-assisted polishing (17th report),” Proc. of JSPE Semestrial Meeting, pp. 497-498, 2017.
9. [9] H. Deng, K. Hosoya, Y. Imanishi, K. Endo, and K. Yamamura, “Electro-chemical mechanical Polishing of single-crystal SiC using CeO2 slurry,” Electrochem. Commun., Vol.52, pp. 5-8, 2015.
10. [10] X. Yang, K. Kawai, K. Arima, and K. Yamamura, “Electrochemical mechanical polishing of 4H-SiC (0001) with different grinding stones,” Proc. of the 21st Int. Symp. on Advances in Abrasive Technology, 90, 2018.
11. [11] T. Tanaka, M. Takizawa, and A. Hata, “Verification of the Effectiveness of UV-polishing for 4H-SiC Wafer Using Photocatalyst and Cathilon,” Int. J. Automation Technol., Vol.12, No.2, pp. 160-168, 2018.
12. [12] M. Mekata, T. Kotsuji, M. Ota, K. Egashira, K. Yamaguchi, M. Yamada, and M. Yamada, “Study on UV assisted grinding,” Proc. of the 20th Int. Symp. on Advances in Abrasive Technology, pp. 11-16, 2017.
13. [13] K. Yamaguchi, M. Touge, A. Kubota, T. Nakano, and J. Watanabe, “Study on High Efficiency Mirror Finished Technique of Single-Crystal SiC Substrate,” J. of the Japan Society for Precision Engineering, Vol.77, No.1, pp. 116-120, 2011.
14. [14] T. Kotsuji et al., “Study on UV-assisted grinding of SiC,” Proc. of 16th Int. Conf. on Precision Engineering, C205-8238, 2016.
15. [15] K. Yamaguchi, M. Touge, A. Kubota, T. Murata, J. Watanabe, Y. Toyohuku, and Y. Sawami, “Effect of paricles on UV-polishing characteristics of single crystal SiC substrate,” J. of the Japan Society for Abrasive Technology, Vol.55, No.4, pp. 220-225, 2011.
16. [16] Y. Nanbu, M. Touge, T. Sakamoto, A. Kubota, N. Touge, and Y. Hidai, “Development of UV-assisted precision truing method for highly-alighned diamond wheel,” 2012 Autumn Meeting of the Japan Society for Precision Engineering, pp. 733-734, 2012 (in Japanese).
17. [17] N. Suzuki, “XPS Measurement of Organic Thin Film on Solid Surface and its Application,” J. of Surface Analysis, Vol.16, No.1, pp. 12-13, 2009.
18. [18] T. Sakamoto, T. Inaki, K. Oda, M. Touge, and T. Fujita, “Ultraviolet-assisted polishing of 4 inch SiC substrate,” J. of the Japan Society for Abrasive Technology, Vol.58, No.4, pp. 235-240, 2014.
19. [19] S. Sasaki, “Surface Texturing for Improvement of Tribological Properties,” J. of The Surface Finishing Society of Japan, Vol.65, No.12, pp. 568-572, 2014.
20. [20] J. Kim and S. Miyake, “Nanometer Scale Protuberance and Groove of Silicon by Mechano-chemical Action and its Application of Etching Mask,” J. of the Japan Society for Precision Engineering, Vol.68, No.5, pp. 695-699, 2002.