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. 2023 May 22;13(10):1694.
doi: 10.3390/nano13101694.

Crystallization of Copper Films on Sapphire Substrate for Large-Area Single-Crystal Graphene Growth

Maxim Komlenok  1 , Pavel Pivovarov  1 , Alexey Popovich  1 , Vladimir Cheverikin  2 , Alexey Romshin  1 , Maxim Rybin  1 , Elena Obraztsova  1
Affiliations

Crystallization of Copper Films on Sapphire Substrate for Large-Area Single-Crystal Graphene Growth

Maxim Komlenok et al. Nanomaterials (Basel). .

Abstract

Chemical vapor deposition synthesis of graphene on polycrystalline copper substrates from methane is a promising technique for industrial production and application. However, the quality of grown graphene can be improved by using single-crystal copper (111). In this paper, we propose to synthesize graphene on epitaxial single-crystal Cu film deposited and recrystallized on a basal-plane sapphire substrate. The effect of film thickness, temperature, and time of annealing on the size of copper grains and their orientation is demonstrated. Under optimized conditions, the copper grains with the (111) orientation and a record size of several millimeters are obtained, and the single-crystal graphene is grown over their entire area. The high quality of synthesized graphene has been confirmed by Raman spectroscopy, scanning electron microscopy, and the sheet resistance measurements by the four point probe method.

Keywords: copper annealing; copper crystallization; copper thin films; cvd synthesis; grain; graphene monolayer.

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Conflict of interest statement

The authors declare no conflict of interest.

Figures

Figure 1
Figure 1
The optical images of copper film with thickness of 3 μm annealed at pressure P = 10 mBar and for t = 90 min at different temperatures: (a) T1 = 1000 °C; (b) T2 = 1030 °C; and (c) T3 = 1050 °C.
Figure 2
Figure 2
The optical images of copper film with different thicknesses annealed at fixed temperature T = 1030 °C and time t = 90 min: (a) d1 =1.1 μm; (b) d2 =1.2 μm; (c) d3 =2.7 μm; and (d) d4 =3.9 μm. EBSD map of the copper film obtained from areas corresponding to optical images: (e) d2 = 1.2 μm; (f) d3 = 2.7 μm. Inverse pole figure corresponding to EBSD data (g); Cu (111) pole figures for the copper film with thickness d2 = 1.2 μm (h) and d3 = 2.7 μm (i).
Figure 3
Figure 3
Images of surface of the copper film with thickness d =2.4μm annealed at temperature T = 1030 °C and time t = 180 min: the optical image (a), EBSD map with inverse pole figure in inset (b), and Cu (111) pole figure (c).
Figure 4
Figure 4
SEM images of graphene synthesized on copper films with thickness: (a) d = 1.2 μm; (b) d = 2.4 μm.
Figure 5
Figure 5
Raman spectra of graphene synthesized on copper film with thickness d = 2.4 μm.
Figure 6
Figure 6
Raman mapping of the three spectra parameters on the area of 300 × 400 µm2 with a resolution of 10 µm: (a) the D/G peak intensity ratio, (b) the 2D/G peak intensity ratio, and (c) the 2D peak FWHM. The bar corresponds to 100 µm.
Figure 7
Figure 7
Optical image of graphene synthesized on copper film with thickness of 2.4 μm and transferred onto Si/SiO2 substrate.
See this image and copyright information in PMC

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References

    1. Xu X., Zhang Z., Dong J., Yi D., Niu J., Wu M., Lin L., Yin R., Li M., Zhou J., et al. Ultrafast epitaxial growth of metre-sized single-crystal graphene on industrial Cu foil. Sci. Bull. 2017;62:1074–1080. doi: 10.1016/j.scib.2017.07.005. - DOI - PubMed
    1. Huang B.-R., Hung S.-C., Ho Y.-S., Chen Y.-S., Yang W.-D. The Efficiency Study of Graphene Synthesis on Copper Substrate via Chemical Vapor Deposition Method with Methanol Precursor. Nanomaterials. 2023;13:1136. doi: 10.3390/nano13061136. - DOI - PMC - PubMed
    1. Yang K., Liu J., Jiang R., Gong Y., Zeng B., Yi Z., Gao Q., Yang J., Chi F., Liu L. Synthesis of Single-Crystal Graphene on Copper Foils Using a Low-Nucleation-Density Region in a Quartz Boat. Micromachines. 2021;12:1236. doi: 10.3390/mi12101236. - DOI - PMC - PubMed
    1. Nguyen D.T., Chiang W.Y., Su Y.H., Hofmann M., Hsieh Y.P. Solid-diffusion-facilitated cleaning of copper foil improves the quality of CVD graphene. Sci. Rep. 2019;9:257. doi: 10.1038/s41598-018-36390-4. - DOI - PMC - PubMed
    1. Kondrashov I., Komlenok M., Pivovarov P., Savin S., Obraztsova E., Rybin M. Preparation of Copper Surface for the Synthesis of Single-Layer Graphene. Nanomaterials. 2021;11:1071. doi: 10.3390/nano11051071. - DOI - PMC - PubMed

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