| AVS 56th International Symposium & Exhibition | |
| Graphene Topical Conference | Monday Sessions |
| Session GR-MoM |
| Session: | Graphene and 2D Carbon Nanostructures |
| Presenter: | J. Mun, KAIST, Republic of Korea |
| Authors: | J. Mun, KAIST, Republic of Korea C. Hwang, Korea Research Institute of Standards and Science, Republic of Korea S. Lim, National Nano Fab Center, Republic of Korea B.J. Cho, KAIST, Republic of Korea |
| Correspondent: | Click to Email |
Recent study on graphene synthesis on metal thin film by chemical vapor deposition in a hydrocarbon ambient has shown promising results for the feasibility of formation of graphene layer over a large area.1-4 However the graphene layer grown on metal thin film shows various kinds of defects on its surface such as islands of thick graphene layers, carbon dumps, and wrinkles from the different thermal expansion coefficient between metal and carbon, and so on.2-3 Control of such defects is critical for the technique to be useful, but the mechanism of the defect formation has not been well studied so far. In this work, the effect of various process conditions which affect the quality of graphene on nickel thin film is carefully investigated, including nickel thin film deposition process, ramping up ambient, annealing ambient, annealing temperature, thickness of nickel thin film, etc. During the high temperature annealing process, nickel thin film becomes highly agglomerated and thereby the surface becomes quite rough. Since the segregated carbon amount at nickel grain boundary is different from that segregated from crystalline nickel inside the grain, the agglomeration of nickel directly affects the thickness uniformity of graphene and roughness of graphene surface. It is found that the deposition process of nickel thin film affects the agglomeration and the e-beam evaporation of nickel has shown less agglomeration upon annealing, compared to physical sputtering. It is also found that the annealing temperature in CH4 is a critical factor to control the amount of thick graphite island on graphene. Furthermore, it is found that the gas ambient during ramping up affects the deformation of nickel thin film. All such detailed process conditions on graphene formation on nickel thin film are carefully investigated and will be presented.
1Q. Yu et al., Appl. Phys. Lett. 93, 113103 (2008).
2A. Reina et al., Nano Lett. 9, 31 (2009)
3K. S. Kim et al., Nature 457, 706 (2009)
4L. G. D. Arco et al., IEEE Trans. Nanotech. 8, 135 (2009)