Paper 2D+TF-WeM5
Growth of Graphene on Cubic Silicon Carbide on Silicon Substrates

Wednesday, November 9, 2016, 9:20 am, Room 103B

Graphene is a two-dimensional sheet of sp² carbon atoms with extraordinary high mobility and quantum properties that makes it a promising candidate for future electronics. Large-scale production of graphene is paramount for the development of graphene-based electronics. This thesis focused on the synthesis and characterization of graphene layers. Two methods were used to grow graphene films. First, graphene films were epitaxially grown on silicon carbide substrates by thermal decomposition of SiC at high temperatures and low pressures. An in-house built reactor consisting of an induction furnace was used to form epitaxial films for electronic applications. Second, chemical vapor deposition was used for direct graphene synthesis on 3C-SiC using copper as a catalyst. In the thermal CVD processes, hydrogen and methane gases were used as precursors. Methane acts as a carbon source, while annealing and cooling were done in a hydrogen environment. Different polytypes of silicon carbide (6H-SiC and 3C-SiC) and their crystal orientations were exploited as substrates to form epitaxial graphene. A hetero-epitaxial 3C-SiC epilayer was first deposited on Si substrate using the chemical vapor deposition technique in the cold wall, low-pressure horizontal CVD reactor. The reactor temperature, argon pressure, flow rate and concentration of different gases (propane, silane, hydrogen and argon) was investigated to control the growth of 3C-SiC and graphene sublimation rate. The resulting graphene films were confirmed using Raman spectroscopy. Further, graphene films have been characterized with the tools of atomic force microscopy (AFM) and scanning electron microscopy (SEM). Mobility, electrical resistivity and carrier density measurements were taken using Hall effect measurements.