Argonne National Laboratory,
Keywords: graphene, wafer-scale growth
Summary:Although great progress have been made on growing large area, high quality graphene on copper, the fact that transfer process (dry or wet) is required in order to utilize them in any electronic applications, the incorporation of impurities cannot be avoided completely putting limits on exploiting excellent intrinsic properties of graphene for various applications. Interaction of one atom thick graphene with the substrate material is another concern and therefore chemical inert substrate is preferred. Diamond offers multiple unique properties, such as high phonon energy, low trap density, and high thermal conductivity, which make it an ideal substrate for fabricating graphene devices on diamond . We demonstrate a novel process to grow large area single and multilayer graphene directly on the diamond thin film deposited on silicon wafer thus eliminating the need for graphene transfer . Here, we introduce a direct approach of transforming diamond into the high quality single and multilayer graphene layers using rapid thermal annealing process facilitated by nickel (Ni) thin film catalyst on top. We show that the process can be tuned to grow single or multilayer graphene on wafer scale with good electronic properties. Molecular dynamics simulations elucidate the mechanism of graphene growth on diamond. Inter-diffusion of nickel through diamond grain boundaries amorphizes carbon and the subsequent counter diffusion of carbon facilitate graphene nucleation enabling rapid lateral growth of graphene on polycrystalline diamond. Additionally, we demonstrate the lateral growth of single domain, free-standing graphene over micron sized pre-fabricated holes, opening new possibilities for future graphene/diamond based electronics. References:  Graphene-on-diamond devices with increased current-carrying capacity: Carbon sp2-on-sp3 planar technology Jie Yu, Guanxiong Liu, Anirudha V. Sumant, Vivek Goyal, Alexander A. Balandin Nano Letters, 12(3), 1603 (2012).  Metal-induced rapid transformation of diamond into single and multilayer graphene on wafer- scale Diana Berman, Sanket Deshmukh, Badri Narayanan, Subramanian Sankaranarayanan, Z. Yan, Alexander Balandin, Alexander Zinovev, Daniel Rosenmann, and Anirudha V. Sumant Nature Communications 7, 12099 (2016).