Rapid characterization of wafer-scale 2D material: Epitaxial graphene and graphene nanoribbons on SiC

We demonstrate that the confocal laser scanning microscopy (CLSM) provides a non-destructive, highly-efficient characterization method for large-area epitaxial graphene and graphene nanostructures on SiC substrates, which can be applied in ambient air without sample preparation and is insusceptible to surface charging or surface contamination. Based on the variation of reflected intensity from regions covered by interfacial layer, single layer, bilayer, or few layer graphene, and through the correlation to the results from Raman spectroscopy and SPM, CLSM images with a high resolution (around 150 nm) reveal that the intensity contrast has distinct feature for undergrown graphene (mixing of dense, parallel graphene nanoribbons and interfacial layer), continuous graphene, and overgrown graphene. Moreover, CLSM has a real acquisition time hundreds of times faster per unit area than the supplementary characterization methods. We believe that the confocal laser scanning microscope will be an indispensable tool for mass-produced epitaxial graphene or applicable 2D materials.

[1]  I. Calizo,et al.  Epitaxial graphene homogeneity and quantum Hall effect in millimeter-scale devices. , 2016, Carbon.

[2]  R. Myers-Ward,et al.  Atmospheric doping effects in epitaxial graphene: correlation of local and global electrical studies , 2016, 1804.09592.

[3]  C. Stampfer,et al.  Raman spectroscopy as probe of nanometre-scale strain variations in graphene , 2014, Nature Communications.

[4]  D. Newell,et al.  Low carrier density epitaxial graphene devices on SiC. , 2014, Small.

[5]  Giuseppe Iannaccone,et al.  Electronics based on two-dimensional materials. , 2014, Nature nanotechnology.

[6]  Alexei Zakharov,et al.  Layer-number determination in graphene on SiC by reflectance mapping , 2014 .

[7]  A. Zakharov,et al.  Morphological and electronic properties of epitaxial graphene on SiC , 2014 .

[8]  T. Murphy,et al.  Sensitive room-temperature terahertz detection via the photothermoelectric effect in graphene. , 2013, Nature nanotechnology.

[9]  Olga Kazakova,et al.  Express optical analysis of epitaxial graphene on SiC: impact of morphology on quantum transport. , 2013, Nano letters.

[10]  R. Yakimova,et al.  Standardization of surface potential measurements of graphene domains , 2013, Scientific Reports.

[11]  Tian Shen,et al.  Graphene Epitaxial Growth on SiC(0001) for Resistance Standards , 2013, IEEE Transactions on Instrumentation and Measurement.

[12]  R. Yakimova,et al.  Identification of epitaxial graphene domains and adsorbed species in ambient conditions using quantified topography measurements , 2012 .

[13]  C. Dimitrakopoulos,et al.  State-of-the-art graphene high-frequency electronics. , 2012, Nano letters.

[14]  A. Ferrari,et al.  Graphene field-effect transistors as room-temperature terahertz detectors. , 2012, Nature materials.

[15]  R. Yakimova,et al.  Precision comparison of the quantum Hall effect in graphene and gallium arsenide , 2012, 1202.2985.

[16]  H. Bechtel,et al.  Graphene plasmonics for tunable terahertz metamaterials. , 2011, Nature nanotechnology.

[17]  T. Ohta,et al.  The role of carbon surface diffusion on the growth of epitaxial graphene on SiC , 2010 .

[18]  C. Dimitrakopoulos,et al.  100-GHz Transistors from Wafer-Scale Epitaxial Graphene , 2010, Science.

[19]  M. Syväjärvi,et al.  Towards a quantum resistance standard based on epitaxial graphene. , 2009, Nature nanotechnology.

[20]  P. Campbell,et al.  Correlating Raman spectral signatures with carrier mobility in epitaxial graphene: a guide to achieving high mobility on the wafer scale. , 2009, Nano letters.

[21]  J. Robinson,et al.  Raman topography and strain uniformity of large-area epitaxial graphene. , 2008, Nano letters.

[22]  U. Starke,et al.  Raman spectra of epitaxial graphene on SiC and of epitaxial graphene transferred to SiO2. , 2008, Nano letters.

[23]  N. Peres,et al.  Fine Structure Constant Defines Visual Transparency of Graphene , 2008, Science.

[24]  Ralf Graupner,et al.  Raman spectra of epitaxial graphene on SiC(0001) , 2008 .

[25]  H. R. Krishnamurthy,et al.  Monitoring dopants by Raman scattering in an electrochemically top-gated graphene transistor. , 2008, Nature nanotechnology.

[26]  Wei Chen,et al.  Raman spectroscopy of epitaxial graphene on a SiC substrate , 2008, 0803.1878.

[27]  Andre K. Geim,et al.  Raman spectrum of graphene and graphene layers. , 2006, Physical review letters.

[28]  P. Hansma,et al.  Atomic force microscopy , 1990, Nature.