Characterization of the Electronic Properties and Strain Sensitivity of Graphene Formed by C2H2 Chemical Vapor Deposition

2015 ◽  
Author(s):  
Meng Yang ◽  
Masato Ohnishi ◽  
Ken Suzuki ◽  
Hideo Miura
Keyword(s):  
Chemical Vapor Deposition ◽  
Tensile Test ◽  
Electronic Properties ◽  
Vapor Deposition ◽  
Field Effect Transistors ◽  
Chemical Vapor ◽  
Single Layer Graphene ◽  
Gauge Factor ◽  
Nucleation Density ◽  
Strain Sensitivity

We succeed in synthesizing large-area single-layer graphene sheets with different grain size using C2H2 chemical vapor deposition process. Our graphene shows high uniformity and low sheet resistance to 1080Ω/□. By fabricating graphene-based field effect transistors (FETs), the relation between the nucleation density and the electronic properties of CVD grpahene are investigated. We found that the nucleation density can severely affect the defects formation in graphene, leading to the change in the electronic properties of graphene. We also check the strain sensitivity of CVD graphene. The as-grown graphene/Cu film was fixed onto the SiO2/Si substrate with a double-sided tape. The strain device is fabricated directly on the graphene-coated Cu foils by using the standard photolithography and reactive ion etching (RIE) process. Then the device is transferred onto a stretchable and flexible polydimethysiloxane (PDMS) substrate. By using a motorized stage, the tensile test is performed to investigate the piezoresistive properties of graphene-based strain sensors. The one-dimensional tensile test is performed to investigate the piezoresistive properties. A gauge factor 3.4 was achieved under the tensile deformation.

scholarly journals Investigation of electronic properties of chemical vapor deposition grown single layer graphene via doping of thin transparent conductive films

RSC Advances ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 3096-3103
Author(s):  
Anand Kumar Singh ◽  
Vivek Chaudhary ◽  
Arun Kumar Singh ◽  
S. R. P. Sinha
Keyword(s):  
Chemical Vapor Deposition ◽  
Charge Carrier ◽  
Electronic Properties ◽  
Vapor Deposition ◽  
Optoelectronic Devices ◽  
Single Layer ◽  
Chemical Vapor ◽  
Single Layer Graphene ◽  
Conductive Films ◽  
Layer Graphene

The tuning of charge carrier of graphene is a potential step for the realization of multifunctional use in current electronic/optoelectronic devices.

Quantitative Modelling of Nucleation Kinetics in Experiments for Poly-Si Growth on Sio2 by Hot-Wire Chemical Vapor Deposition

2001 ◽  
Vol 664 ◽  
Author(s):  
Maribeth Swiatek ◽  
Jason K. Holt ◽  
Harry A. Atwater
Keyword(s):  
Activation Energy ◽  
Grain Size ◽  
Chemical Vapor Deposition ◽  
Vapor Deposition ◽  
Chemical Vapor ◽  
Nucleation Density ◽  
Hot Wire ◽  
Nucleation Kinetics ◽  
Temperature Dependent ◽  
Cluster Density

ABSTRACTWe apply a rate-equation pair binding model of nucleation kinetics [1] to the nucleation of Si islands grown by hot-wire chemical vapor deposition on SiO2 substrates. Previously, we had demonstrated an increase in grain size of polycrystalline Si films with H2 dilution from 40 nm using 100 mTorr of 1% SiH4 in He to 85 nm with the addition of 20 mTorr H2. [2] This increase in grain size is attributed to atomic H etching of Si monomers rather than stable Si clusters during the early stages of nucleation, decreasing the nucleation density. Atomic force microscopy (AFM) measurements show that the nucleation density increases sublinearly with time at low coverage, implying a fast nucleation rate until a critical density is reached, after which grain growth begins. The nucleation density decreases with increasing H2 dilution (H2:SiH4), which is an effect of the etching mechanism, and with increasing temperature, due to enhanced Si monomer diffusivity on SiO2. From temperature-dependent measurements, we estimate the activation energy for surface diffusion of Si monomers on SiO2 to be 0.47 ± 0.09 eV. Simulations of the temperature-dependent supercritical cluster density lead to an estimated activation energy of 0.42 eV ± 0.01 eV and a surface diffusion coefficient prefactor of 0.1 ± 0.03 cm2/s. H2-dilution-dependent simulations of the supercritical cluster density show an approximately linear relationship between the H2 dilution and the etch rate of clusters.

Achieving High Nucleation Density of Diamond Film Under Low Pressures in Hot-Filament Chemical Vapor Deposition

1994 ◽  
Vol 363 ◽  
Author(s):  
Yan Chen ◽  
Jun Mei ◽  
Qijin Chen ◽  
Zhangda Lin
Keyword(s):  
Chemical Vapor Deposition ◽  
Diamond Film ◽  
Vapor Deposition ◽  
Crystalline Silicon ◽  
Chemical Vapor ◽  
Nucleation Density ◽  
Heteroepitaxial Growth ◽  
Hot Filament ◽  
Low Pressures ◽  
Gaseous Source

AbstractDiamond have been deposited rapidly under low pressures (<0.1 Torr) via hot filament chemical vapor deposition (HFCVD) on either scratched or mirror-smooth single crystalline silicon and titanium with nucleation densities of 109–1011/cm2. The nucleation density increases with the pressure decreases. Hydrogen and methane were used as the gaseous source. Raman spectroscopy and scanning electron microscopy(SEM) were used to analyze the obtained films. This result breaks through the limit that diamond film can only be synthesized above 10 Torr, showing a promising prospect that, as is essential for heteroepitaxial growth of monocrystalline diamond films, diamond film can be easily nucleated on unscratched substrate via Hot Filament CVD.

Nucleation and selected area deposition of diamond by biased hot filament chemical vapor deposition

1995 ◽  
Vol 10 (2) ◽  
pp. 425-430 ◽  
Author(s):  
W. Zhu ◽  
F.R. Sivazlian ◽  
B.R. Stoner ◽  
J.T. Glass
Keyword(s):  
Chemical Vapor Deposition ◽  
Vapor Deposition ◽  
Substrate Surface ◽  
Chemical Vapor ◽  
Wire Mesh ◽  
Reactor Wall ◽  
Nucleation Density ◽  
Si Substrate ◽  
Diamond Nucleation ◽  
Hot Filament

This paper describes a process for uniformly enhancing the nucleation density of diamond films on silicon (Si) substrates via dc-biased hot filament chemical vapor deposition (HFCVD). The Si substrate was negatively biased and the tungsten (W) filaments were positively biased relative to the grounded stainless steel reactor wall. It was found that by directly applying such a negative bias to the Si substrate in a typical HFCVD process, the enhanced diamond nucleation occurred only along the edges of the Si wafer. This resulted in an extremely nonuniform nucleation pattern. Several modifications were introduced to the design of the substrate holder, including a metal wire-mesh inserted between the filaments and the substrate, in the aim of making the impinging ion flux more uniformly distributed across the substrate surface. With such improved growth system designs, uniform enhancement of diamond nucleation across the substrate surface was realized. In addition, the use of certain metallic wire mesh sizes during biasing also enabled patterned or selective diamond deposition.

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