scholarly journals Structure of Carbonic Layer in Ohmic Contacts: Comparison of Silicon Carbide/Carbon and Carbon/Silicide Interfaces

2013 ◽  
Vol 2013 ◽  
pp. 1-11 ◽  
Author(s):  
Paweł Borowicz ◽  
Adrian Kuchuk ◽  
Zbigniew Adamus ◽  
Michał Borysiewicz ◽  
Marek Ekielski ◽  
...  
Keyword(s):  
Silicon Carbide ◽  
Raman Spectroscopy ◽  
Thermal Treatment ◽  
Ohmic Contacts ◽  
Carbon Film ◽  
Graphene Layers ◽  
Three Samples ◽  
Nickel Silicon

The structure of carbonic layer in three samples composed of 4H polytype of silicon carbide and the following sequence of layers: carbon/nickel/silicon/nickel/silicon was investigated with Raman spectroscopy. Different thermal treatment of the samples led to differences in the structure of carbonic layer. Raman measurements were performed with visible excitation focused on two interfaces: silicon carbide/carbon and carbon/silicide. The results showed differences in the structure across carbon film although its thickness corresponds to 8/10 graphene layers.

Graphene Layers on Silicon Carbide Studied by Raman Spectroscopy

2008 ◽  
Vol 600-603 ◽  
pp. 567-570 ◽  
Author(s):  
Jonas Röhrl ◽  
Martin Hundhausen ◽  
Konstantin V. Emtsev ◽  
Thomas Seyller ◽  
Lothar Ley
Keyword(s):  
Silicon Carbide ◽  
Raman Spectroscopy ◽  
Light Scattering ◽  
Graphene Layer ◽  
Monolayer Graphene ◽  
Spectroscopy Study ◽  
Graphene Layers ◽  
Layer Graphene ◽  
Micro Raman Spectroscopy ◽  
Few Layer Graphene

We present a micro-Raman spectroscopy study on single- and few layer graphene (FLG) grown on the silicon terminated surface of 6H-silicon carbide (SiC). On the basis of the 2D-line (light scattering from two phonons close to the K-point in the Brillouin zone) we distinguish graphene mono- from bilayers or few layer graphene. Monolayers have a 2D-line consisting of only one component, whereas more than one component is observed for thicker graphene layers. Compared to the graphite the monolayer graphene lines are shifted to higher frequencies. We tentatively ascribe the corresponding phonon hardening to strain in the first graphene layer.

Strain and Charge in Epitaxial Graphene on Silicon Carbide Studied by Raman Spectroscopy

2010 ◽  
Vol 645-648 ◽  
pp. 603-606 ◽  
Author(s):  
Jonas Röhrl ◽  
Martin Hundhausen ◽  
Florian Speck ◽  
Thomas Seyller
Keyword(s):  
Silicon Carbide ◽  
Raman Spectroscopy ◽  
Graphene Layer ◽  
Tensile Strain ◽  
Lattice Mismatch ◽  
Mechanical Strain ◽  
Epitaxial Graphene ◽  
Preparation Process ◽  
High Temperature Annealing ◽  
Graphene Layers

The phonon frequencies of epitaxial graphene on silicon carbide (SiC) depend on mechanical strain and charge transfer from the substrate to the epitaxial layer. Strain and doping depend on the preparation process and on the number of graphene layers. We measured the phonon frequencies by Raman spectroscopy and compare the results between epitaxial layers fabricated by high temperature annealing and by hydrogen intercalation of the covalently bound graphene layer of the 6 p 3 6 p 3 reconstructed SiC surface. Only the latter graphene layer shows tensile strain, which can partly be explained by lattice mismatch between substrate and epitaxial graphene.

scholarly journals Visible and Deep-Ultraviolet Raman Spectroscopy as a Tool for Investigation of Structural Changes and Redistribution of Carbon in Ni-Based Ohmic Contacts on Silicon Carbide

2012 ◽  
Vol 2012 ◽  
pp. 1-11 ◽  
Author(s):  
Paweł Borowicz ◽  
Adrian Kuchuk ◽  
Zbigniew Adamus ◽  
Michał Borysiewicz ◽  
Marek Ekielski ◽  
...  
Keyword(s):  
Silicon Carbide ◽  
Raman Spectroscopy ◽  
Structural Changes ◽  
Layer Structure ◽  
Carbon Layer ◽  
Raman Shift ◽  
Range Analysis ◽  
Silicide Layer ◽  
Deep Ultraviolet ◽  
Nickel Silicon

Three samples of 4H polytype of silicon carbide (4H-SiC) covered with the following sequence of layers: carbon/nickel/silicon/nickel/silicon were investigated with micro-Raman spectroscopy. Different thermal treatments of each sample result in differences of carbon layer structure and migration of carbon atoms thorough silicide layer. Two ranges of Raman shift were investigated. The first one is placed between 1000 cm−1 and 2000 cm−1. The main carbon bands D and G are observed in this range. Analysis of the positions of these bands and their intensity ratio enables one to determine the graphitization degree of carbon layer. Additional information about the changes of the carbon layer structure was derived from analysis of 2D band placed around 2700 cm−1. Application of deep ultraviolet excitation delivered information about the structure of carbon layer formed on the free surface of silicides and the distribution of the carbon inside the silicide layer.

CVD Growth of Graphene on SiC (0001): Influence of Substrate Offcut

2017 ◽  
Vol 897 ◽  
pp. 731-734 ◽  
Author(s):  
Roy Dagher ◽  
Benoit Jouault ◽  
Matthieu Paillet ◽  
Maxime Bayle ◽  
Luan Nguyen ◽  
...  
Keyword(s):  
Silicon Carbide ◽  
Raman Spectroscopy ◽  
Chemical Vapor Deposition ◽  
Vapor Deposition ◽  
Chemical Vapor ◽  
Argon Atmosphere ◽  
Graphene Layers ◽  
Cvd Growth ◽  
Influence Of Substrate ◽  
The Ideal

In this study we report the growth of graphene on different silicon carbide substrates by chemical vapor deposition (CVD) in order to understand the influence of the substrate offcut on the graphene layers. For this purpose, graphene was grown on substrates with different offcuts, under hydrogen-argon atmosphere, and analyzed using AFM, LEED and Raman spectroscopy. We discuss the morphology and strain in graphene, and finally the ideal offcut for graphene growth.

Thermodynamics and Microstructure Development in the Thin Film Reaction of Aluminum on Silicon Carbide

1995 ◽  
Vol 403 ◽  
Author(s):  
T. S. Hayes ◽  
F. T. Ray ◽  
K. P. Trumble ◽  
E. P. Kvam
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Silicon Carbide ◽  
Ohmic Contacts ◽  
Microstructure Development ◽  
P Type ◽  
Microstructural Studies

AbstractA refined thernodynamic analysis of the reaction between molen Al and SiC is presented. The calculations indicate much higher Si concentrations for saturation with respect to AkC 3 formation than previously reported. Preliminary microstructural studies confirm the formation of interfacial A14C3 for pure Al thin films on SiC reacted at 9000C. The implications of the calculations and experimental observations for the production of ohmic contacts to p-type SiC are discussed.

scholarly journals Manipulating the surface-enhanced Raman spectroscopy (SERS) activity and plasmon-driven catalytic efficiency by the control of Ag NP/graphene layers under optical excitation

Nanophotonics ◽  
2021 ◽  
Vol 10 (5) ◽  
pp. 1529-1540
Author(s):  
Xianwu Xiu ◽  
Liping Hou ◽  
Jing Yu ◽  
Shouzhen Jiang ◽  
Chonghui Li ◽  
...  
Keyword(s):  
Raman Spectroscopy ◽  
Hot Spot ◽  
Catalytic Efficiency ◽  
Surface Enhanced Raman Spectroscopy ◽  
In Situ Monitoring ◽  
Excitation Beam ◽  
Graphene Layers ◽  
Cu Film ◽  
Surface Enhanced ◽  
Surface Enhanced Raman

Abstract Highly efficient plasmon-driven catalysis and excellent surface-enhanced Raman spectroscopy (SERS) performance are proportional to the square of the local electromagnetic field (hot spot). However, a proven way to realize the enhancement in intensity and density of “hot spot” still needs to be investigated. Here, we report on multilayered Ag nanoparticle (Ag NP)/graphene coupled to an underlying Cu film system (MAgNP-CuF) which can be used as an effective SERS substrates realizing ultra-sensitive detection for toxic molecules and in situ monitoring the plasmon-driven reaction for p-nitrothiophenol (PNTP) to p,p′-dimercaptobenzene (DMAB) conversion. The mechanism of ultra-sensitive SERS response and catalytic reaction is investigated via Ag NP/graphene layer-dependent experiments combined with theoretical simulations. The research found that the intensity and density of “hot spot” can be effectively manipulated by the number of plasmonic layers, and the bottom Cu film could also reflect the scattered and excitation beam and would further enhance the Raman signals. Moreover, the MAgNP-CuF exhibits outstanding performance in stability and reproducibility. We believe that this concept of multilayered plasmonic structures would be widely used not only in the field of SERS but also in the wider research in photocatalysis.

Mechanical properties of nickel silicon carbide nanocomposites

2002 ◽  
Vol 328 (1-2) ◽  
pp. 137-146 ◽  
Author(s):  
A.F. Zimmerman ◽  
G. Palumbo ◽  
K.T. Aust ◽  
U. Erb
Keyword(s):  
Mechanical Properties ◽  
Silicon Carbide ◽  
Nickel Silicon

Pinned and unpinned epitaxial graphene layers on SiC studied by Raman spectroscopy

2012 ◽  
Vol 111 (11) ◽  
pp. 114307 ◽  
Author(s):  
K. Grodecki ◽  
J. A. Blaszczyk ◽  
W. Strupinski ◽  
A. Wysmolek ◽  
R. Stępniewski ◽  
...  
Keyword(s):  
Raman Spectroscopy ◽  
Epitaxial Graphene ◽  
Graphene Layers

Raman Spectroscopy of Epitaxial Si/Si1-xGe, xHeterostructures

1998 ◽  
Vol 533 ◽  
Author(s):  
Ran Liu ◽  
Stefan Zollner ◽  
Ming Liaw ◽  
David O'meara ◽  
Nigel Cave
Keyword(s):  
Raman Spectroscopy ◽  
Thermal Treatment ◽  
Raman Scattering ◽  
Buffer Layer ◽  
Excellent Agreement ◽  
Lattice Mismatch ◽  
Theoretical Curve ◽  
Sum Rule ◽  
Si Substrates ◽  
Strain Coefficient

AbstractRaman scattering studies were carried out on epi Si/Si1-xGex (x = 0.1 to 0.3) heterostructures consisting of a thin Si cap layer (100 - 400 A˚), a grade-down Si1-xGex layer, a constant Si1-xGex, buffer layer and a grade-up graded Si1-xGex layer on (100) oriented Si substrates. Different Ge composition, Si1-xGex layer thicknesses and thermal treatment were used to achieve different relaxation in the Si1-xGex layers. It has been revealed that, to a very good approximation, the absolute strains in the cap Si and constant Si1-xGex layers follow a simple sum-rule that is imposed by the lattice mismatch between unstrained Si and completely relaxed Si1-x Gex. This sum rule can be used to determine the Ge composition and stresses in both cap Si and constant Si1-xGex layers. Excellent agreement was found between the theoretical curve obtained with LO phonon strain coefficient b=−930cm−1 and the experimental total strain for all samples, regardless of the degree of the relaxation of the grade-up Si1-xGex layer.

Ohmic Contacts to Silicon Carbide Devices

1992 ◽  
pp. 183-189 ◽  
Author(s):  
M. M. Anikin ◽  
M. G. Rastegaeva ◽  
A. L. Syrkin ◽  
I. V. Chuiko
Keyword(s):  
Silicon Carbide ◽  
Ohmic Contacts
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