scholarly journals Nonmonotonic temperature dependent transport in graphene grown by chemical vapor deposition

2011 ◽  
Vol 84 (3) ◽  
Author(s):  
J. Heo ◽  
H. J. Chung ◽  
Sung-Hoon Lee ◽  
H. Yang ◽  
D. H. Seo ◽  
...  
Keyword(s):  
Chemical Vapor Deposition ◽  
Vapor Deposition ◽  
Chemical Vapor ◽  
Temperature Dependent ◽  
Dependent Transport

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.

Electron Paramagnetic Resonance Studies of Intrinsic Bonding Defects and Impurities in SiO2 Thin Solid Films

1985 ◽  
Vol 61 ◽  
Author(s):  
Robert N. Schwartz ◽  
Marion D. Clark ◽  
Walee Chamulitrat ◽  
Larry Kevan
Keyword(s):  
Electron Paramagnetic Resonance ◽  
Chemical Vapor Deposition ◽  
Vapor Deposition ◽  
Rf Sputtering ◽  
Chemical Vapor ◽  
Temperature Dependent ◽  
Paramagnetic Resonance ◽  
Pressure Chemical ◽  
Defects And Impurities ◽  
Electron Paramagnetic

ABSTRACTElectron paramagnetic resonance (EPR) spectroscopy has been used to identify paramagnetic intrinsic bonding defects and impurities in as-deposited thin solid SiO2 films. Thin films grown by E-beam vacuum deposition, RF sputtering, thermal oxidation of polysilicon, plasma enhanced chemical vapor deposition (PECVD), and low pressure chemical vapor deposition (LPCVD) techniques have been examined. Some of the growth techniques yield films that have paramagnetic centers similar to those found in bulk radiation-damaged vitreous SiO2. A new temperature dependent EPR center was observed in PECVD SiO2 films and has been assigned to trapped NO2. Slow-motional EPR lineshape theory was used to analyze the temperature dependent spectra.

scholarly journals Chemical Vapor Deposition of IrTe2 Thin Films

Crystals ◽  
2020 ◽  
Vol 10 (7) ◽  
pp. 575
Author(s):  
Rui Zhou ◽  
Zhaoyang Zhao ◽  
Juanxia Wu ◽  
Liming Xie
Keyword(s):  
Chemical Vapor Deposition ◽  
Vapor Deposition ◽  
Hexagonal Boron Nitride ◽  
Chemical Vapor ◽  
Spectroscopic Characterization ◽  
Electrical Measurement ◽  
Charge Ordering ◽  
Temperature Dependent ◽  
Raman Spectroscopic

Two-dimensional (2D) IrTe2 has a profound charge ordering and superconducting state, which is related to its thickness and doping. Here, we report the chemical vapor deposition (CVD) of IrTe2 films using different Ir precursors on different substrates. The Ir(acac)3 precursor and hexagonal boron nitride (h-BN) substrate is found to yield a higher quality of polycrystalline IrTe2 films. Temperature-dependent Raman spectroscopic characterization has shown the q1/8 phase to HT phase at ~250 K in the as-grown IrTe2 films on h-BN. Electrical measurement has shown the HT phase to q1/5 phase at around 220 K.

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