Synthesis And Application Of Graphene On Patterned Substrate

Graphene, a single compact layer of sp2-hybridized carbon atoms packed into a honeycomb network, has invited great interest since its first successful fabrication by cleavage in2004. Recently, Graphene is widely investigated because of its outstanding physical properties. Several techniques have been investigated to fabricate graphene such as mechanical exfoliation, thermal decomposition of SiC and chemical vapor deposition (CVD). Large-area and high-quality graphene synthesized by CVD method has showed great potential for device applications. However, most device applications require a transfer process aided by polymethyl methacrylate (PMMA), which usually causes graphene to form cracks when the PMMA is dissolved away, and residues of the transfer process would lead to lower quality graphene. Furthermore, the performance of graphene-based devices will be affected.Patterned growth of graphene at specified locations with required geometries by using catalyst patterns in CVD, in which graphene synthesized with controlled shape, controlled size and corresponding catalyst patterns, in order to meet the graphene patterns required in device fabrication. Graphene could avoid the contamination of transfer process and reserve its properties via this method. However, graphene synthesis on Cu thin films (<1000nm) has not been widely studied. In this paper, we investigated the synthesis of graphene on Cu thin films using CVD.We obtained the optimal growth conditions of CVD process of graphene synthesis on Cu thin films after a series of experiments. Consequently, few-layer graphene which had been characterized by optical microscopy and Raman spectroscopy atomic was synthesized. Conductive atomic force microscopy (AFM) was used to measure the conductivity of metal-graphene contact samples and the result showed that the conductivity of CVD synthesized graphene on Cu thin films is higher than the transferred graphene on same Cu thin films, which was synthesized on25μm Cu foils by conventional CVD method.