single-au.php

IJAT Vol.13 No.2 pp. 230-236
doi: 10.20965/ijat.2019.p0230
(2019)

Paper:

Surface Finishing of Single-Crystal SiC and GaN Wafers Using a Magnetic Tool in H2O2 Solution

Akihisa Kubota

Kumamoto University
2-39-1 Kurokami, Chuo-ku, Kumamoto City, Kumamoto 860-8555, Japan

Corresponding author

Received:
July 26, 2018
Accepted:
January 30, 2019
Published:
March 5, 2019
Keywords:
SiC, GaN, surface smoothing, OH radical, abrasive Fe
Abstract

To remove the microroughness and subsurface damage on the SiC and GaN surface efficiently, a surface finishing technique using a magnetic tool holding iron particles in a hydrogen peroxide solution is developed. This technique utilizes OH radicals generated from the iron catalytic particles in a hydrogen peroxide solution, and can be used to preferentially remove the topmost convex part on the surface, resulting in an atomically smooth surface. We employed this polishing technique to finish the surfaces of 2-inch SiC and 2-inch GaN wafers. The surface roughness before and after finishing was measured by scanning white light interferometric microscopy and atomic force microscopy. In addition, the material removal rate was calculated by weight loss due to the finishing process. The results show that the surface roughness on the SiC and GaN wafers is markedly improved. Moreover, the surface waviness and flatness of these wafers before and after finishing did not deteriorate. Atomic force microscope images indicate that an atomically flat SiC surface with a roughness value below 0.1 nm RMS and a GaN surface with atomic step and terrace structures were achieved. Our proposed finishing technique is effective in improving the surface microroughness of SiC and GaN wafers.

Cite this article as:
A. Kubota, “Surface Finishing of Single-Crystal SiC and GaN Wafers Using a Magnetic Tool in H2O2 Solution,” Int. J. Automation Technol., Vol.13 No.2, pp. 230-236, 2019.
Data files:
References
  1. [1] H. Morkoç, S. Strite, G. B. Gao, M. E. Lin, B. Sverdlov, and M. Burns, “Large-band-gap SiC, III-V nitride, and II-VI ZnSe-based semiconductor device technologies,” J. Appl. Phys., Vol.76, pp. 1363-1398, 1994.
  2. [2] J. R. Grim, M. Benamara, M. Skowronski, W. J. Everson, and V. D. Heydemann, “Transmission electron microscopy analysis of mechanical polishing-related damage in silicon carbide wafers,” Semicond. Sci. Tech., Vol.21, p. 1709, 2006.
  3. [3] H. Aida, H. Takeda, S.-W. Kim, N. Aota, K. Koyama, T. Yamazaki, and T. Doi, “Evaluation of subsurface damage in GaN substrate induced by mechanical polishing with diamond abrasives,” Appl. Surf. Sci., Vol.292, pp. 531-536, 2014.
  4. [4] F.-W. Huo, D.-M. Guo, R.-K. Kang, and G. Feng, “Nanogrinding of SiC wafers with high flatness and low subsurface damage,” Trans. of Nonferrous Metals Society of China, Vol.22, Issue 12, pp. 3027-3033, 2012.
  5. [5] H. Lee, H. Kasuga, H. Ohmori, H. Lee, and H. Jeong, “Application of electrolytic in-process dressing (ELID) grinding and chemical mechanical polishing (CMP) process for emerging hard – brittle materials used in light-emitting diodes,” J. Crystal Growth, Vol.326, Issue 1, pp.140-146, 2011.
  6. [6] Q. S. Yan, S. K. Chen, J. S. Pan, J. B. Lu, and Q. Liu, “Surface and subsurface damage characteristics and material removal mechanism in 6H-SiC wafer grinding,” Mater. Res. Innov., Vol.18, No.2, p. S2-742, 2014.
  7. [7] M. Kikuchi, Y. Takahashi, T. Suga, S. Suzuki, and Y. Bando, “Mechanochemical Polishing of Silicon Carbide Single Crystal with Chromium(III) Oxide Abrasive,” J. Am. Ceram. Soc., Vol.75, No.1, pp. 189-194, 1992.
  8. [8] L. Zhou, V. Audurier, P. Pirouz, and J. A. Powell, “Chemomechanical Polishing of Silicon Carbide,” J. Electrochem. Soc., Vol.144, Issue 6, pp. L161-L163, 1997.
  9. [9] Y. Sano, K. Arima, and K. Yamauchi, “Planarization of SiC and GaN Wafers Using Polishing Technique Utilizing Catalyst Surface Reaction,” ECS J. Solid State Sci. Technol., Vol.2, Issue 8, pp. N3028-N3035, 2013.
  10. [10] X. Shi, G. Pan, Y. Zhou, Z. Gu, H. Gong, and C. Zou, “Characterization of colloidal silica abrasives with different sizes and their chemical – mechanical polishing performance on 4H-SiC (0001),” Appl. Surf. Sci., Vol.307, pp. 414-427, 2014.
  11. [11] U. R. K. Lagudu, S. Isono, S. Krishnan, and S. V. Babu, “Role of ionic strength in chemical mechanical polishing of silicon carbide using silica slurries,” Colloids Surf. A: Physicochem. Eng. Aspects, Vol.445, pp. 119-127, 2014.
  12. [12] S. Hayashi, T. Koga, and M. S. Goorsky, “Chemical mechanical polishing of GaN,” J. Electrochem. Soc., Vol.155, Issue 2, pp. H113-H116, 2008.
  13. [13] H. Yan, X. Xiu, Z. Liu, R. Zhang, X. Hua, Z. Xie, P. Han, Y. Shi, and Y. Zheng, “Chemical mechanical polishing of freestanding GaN substrates,” J. Semicond., Vol.30, No.2, 023003, 2009.
  14. [14] H. Aida, T. Doi, H. Takeda, H. Katakura, S.-W. Kim, K. Koyama, T. Yamazaki, and M. Uneda, “Ultraprecision CMP for Sapphire, GaN, and SiC for Advanced Optoelectronics Materials,” Curr. Appl. Phys., Vol.12, pp. S41-S46, 2012.
  15. [15] H. Aida, S.-W. Kim, T. Suzuki, K. Koyama, N. Aota, T. Doi, and T. Yamazaki, “Surface planarization of GaN-on-sapphire template by chemical mechanical polishing for subsequent GaN homoepitaxy,” ECS J. Solid State Sci. Technol., Vol.3, pp. P163-P168, 2014.
  16. [16] H. Gong, G. Pan, Y. Zhou, X. Shi, C. Zou, and S. Zhanga, “Investigation on the surface characterization of Ga-faced GaN after chemical-mechanical polishing,” Appl. Surf. Sci., Vol.338, pp. 85-91, 2015.
  17. [17] H. Deng, K. Endo, and K. Yamamura, “Plasma-assisted polishing of gallium nitride to obtain a pit-free and atomically flat surface,” CIRP Annals – Manufacturing Technology, Vol.64, No.1, pp. 531-534, 2015.
  18. [18] A. Kubota, K. Yagi, J. Murata, H. Yasui, S. Miyamoto, H. Hara, Y. Sano, and K. Yamauchi, “A study on a surface preparation method for single-crystal SiC using an Fe catalyst,” J. Electron. Mater., Vol.38, Issue 1, pp. 159-163, 2009.
  19. [19] A. Kubota, M, Yoshimura, T, Watayo, Y. Nakanishi, and M. Touge, “Advanced Lapping and Polishing Methods for Planarizing a Single-Crystal 4H-SiC Utilizing Fe Abrasive Particles,” Key Eng. Mater., Vols.447-448, pp. 146-149, 2010.
  20. [20] A. Kubota, M. Yoshimura, S. Fukuyama, C. Iwamoto, and M. Touge, “Planarization of C-face 4H-SiC substrate using Fe particles and hydrogen peroxide solution,” Precis. Eng., Vol.36, Issue 1, pp. 137-140, 2012.
  21. [21] A. Kubota, Y. Ichimori, and M. Touge, “Surface polishing of 2-inch 4H-SiC wafer using Fe abrasive particles,” Key Eng. Mater., Vol.516, pp. 487-491, 2012.
  22. [22] S. Nagae, A. Kubota, and M. Touge, “Development of the Local Polishing Technique for Single-Crystal SiC Wafer,” Key Eng. Mater., Vols.656-657, pp. 204-207, 2015.
  23. [23] B. P. Swain, “The analysis of carbon bonding environment in HWCVD deposited a-SiC:H films by XPS and Raman spectroscopy,” Surf. Coat. Technol., Vol.201, Issues 3-4, pp. 1589-1593, 2006.
  24. [24] Y. Hijikata, H. Yaguchi, M. Yoshikawa, and S. Yoshida, “Composition analysis of SiO2/SiC interfaces by electron spectroscopic measurements using slope-shaped oxide films,” Appl. Surf. Sci., Vol.184, pp. 161-166, 2001.
  25. [25] K. Shimoda, J.-S. Park, T. Hinoki, and A. Kohyama, “Influence of surface structure of SiC nano-sized powder analyzed by X-ray photoelectron spectroscopy on basic powder characteristics,” Appl. Surf. Sci., Vol.253, Issue 24, pp. 9450-9456, 2007.
  26. [26] K. M. Tracy, W. J. Mecouch, R. F. Davis, and R. J. Nemanich, “Preparation and characterixation of atomically clean, stoichiometric surface of n- and p-type GaN(0001),” J. Appl. Phys., Vol.94, No.5, pp. 3163-3172, 2003.
  27. [27] D. Li, M. Sumiya, S. Fuke, D. Yang, D. Que, Y. Suzuki, and Y. Fukuda, “Selective etching of GaN polar surface in potassium hydroxide solution studied by x-ray photoelectron spectroscopy,” J. Appl. Phys., Vol.90, No.8, pp. 4219-4223, 2001.

*This site is desgined based on HTML5 and CSS3 for modern browsers, e.g. Chrome, Firefox, Safari, Edge, Opera.

Last updated on Dec. 06, 2024