▎ 摘　　要

NOVELTY - Method for patterning graphene involves: forming pattern (12) of passivation material on growth substrate (16), where pattern of passivation material defines inverse pattern of exposed surface on growth substrate; and supplying carbon-containing gas to inverse pattern of exposed surface of growth substrate and forming patterned graphene (18) from carbon, where passivation material does not facilitate graphene growth, and inverse pattern of exposed surface of growth substrate facilitates graphene growth on exposed surface of growth substrate. USE - For patterning graphene (claimed) for use in graphene-based devices, such as for high speed electronics, sensors, radiofrequency identification devices (RFIDs), wearable electronics, disposable electronics, displays, and transparent circuitry. ADVANTAGE - The method provides improved method for patterning graphene; whereas such traditional methods suffer from disadvantages such as lack of scalability, fabrication speed or restrictions on target substrate onto which graphene can transferred. Additionally, traditional patterning techniques rely on destructive removal of excess graphene through use of oxygen plasma, ultra-violet ozone, or reactive ion etching, which can decrease quality of graphene and leave rough graphene edges. Further, material deposition and lift off steps for defining graphene patterns have been shown to affect doping of graphene film and graphene-electrode-interface, thus deteriorating performance of fabricated devices. The method is capable of producing higher-quality graphene devices since patterning step is carried out before graphene is synthesized; and thus risk of contaminating graphene in fabrication process can be reduced. Although attempts have been made to obtain patterned graphene by depositing catalytic substrates in desired shape and then growing graphene on substrates, catalytic approach has fundamental limitation as to achievable resolution because patterned catalyst will restructure itself at high process temperatures to decrease its surface free energy, resulting in smoothed-out corners and merged features. Further, deposition of patterns through evaporation increases production cost compared to rolled foils; and such depositions can result in lower-crystalline-quality substrates, which correlates with lower-quality graphene. The method results in production of high quality and low cost graphene-based devices. In the method, patterned graphene can be generated through area-selective chemical-vapor-deposition (CVD) growth. The method includes passivation of defined areas of catalyst material and subsequent selective growth in unpassivated regions, where graphene will grow preferentially i.e. with much greater coverage and continuity in unpassivated regions. The passivation layer can be non-catalytic with respect to carbon-containing gas or is catalytic but not suitable for graphene growth. In addition to hindering growth of graphene, passivation layer can be advantageously formed of material that is immiscible with substrate such as copper, at high temperatures and has high melting point to avoid diffusion of passivation layer on growth substrate. Because passivation material can be patterned with high-degree of precision, subsequently deposited graphene film can have very fine and precise dimensions in pattern, which is inverse to pattern of passivation material. DETAILED DESCRIPTION - Method for patterning graphene involves: forming pattern (12) of passivation material on growth substrate (16), where pattern of passivation material defines inverse pattern of exposed surface on growth substrate; and supplying carbon-containing gas to inverse pattern of exposed surface of growth substrate and forming patterned graphene (18) from carbon, where passivation material does not facilitate graphene growth, and inverse pattern of exposed surface of growth substrate facilitates graphene growth on exposed surface of growth substrate. The exposed surface of growth substrate includes catalyst (preferably transition metal) that decomposes carbon-containing gas to free carbon for forming graphene. The passivation material includes exposed ceramic surface, and is formed by depositing metal layer and oxidizing exposed surface of metal layer to form ceramic surface. The formation of passivation material pattern includes shadow-mask deposition, lithography, or ink-jet printing. The method further involves removing pattern of passivation material from growth substrate after graphene pattern is formed, releasing graphene pattern from growth substrate, and depositing released graphene pattern on new substrate. The growth substrate includes copper surface on which pattern of passivation material is formed, where passivation material is non-alloying with copper. The graphene pattern is deposited with at least one pathway having width of not greater than 1 nm. An INDEPENDENT CLAIM is included for growth substrate with patterned graphene, comprising: growth substrate; passivation pattern comprising material that does not facilitate graphene growth on growth substrate, where passivation pattern defines inverse pattern of exposed surface on growth substrate; and graphene pattern formed preferentially on inverse pattern of growth substrate in comparison with passivation pattern. DESCRIPTION OF DRAWING(S) - The figure shows graphene film formed on sections of metal film not covered by passivation material. Pattern of passivation material (12) Growth substrate (16) Graphene film (18)