Effect of the On/Off Cyclic Modulation Time Ratio of C2H2/H2 Flow on the Low Temperature Deposition of Carbon Nanofilaments

2007 ◽  
Vol 7 (11) ◽  
pp. 3969-3973 ◽  
Author(s):  
Kwang-Duk Kim ◽  
Sung-Hoon Kim ◽  
Nam Seok Kim ◽  
Dong-Uk Kim
Keyword(s):  
Low Temperature ◽  
Gas Flow ◽  
Silicon Oxide ◽  
Chemical Vapor ◽  
Hydrogen Gas ◽  
Etching Time ◽  
Catalyst Precursor ◽  
Time Ratio ◽  
Oxide Substrate ◽  
Initial Deposition

Low temperature (less than 600 °C) deposition of carbon nanofilaments (CNFs) could be achieved on the silicon oxide substrate by thermal chemical vapor deposition system. We used Fe(CO)5 as the catalyst precursor for CNFs formation. For the enhancement of CNFs formation density, the source gas flow was intentionally manipulated as the cyclic on/off modulation of C2H2/H2 flow during the initial deposition stage. The CNFs formation density on silicon oxide substrate could be much enhanced by the cyclic modulation process having the higher growing/etching time ratio (180/30 s). Furthermore, the lattice structures of CNFs developed into carbon nanotubes at the higher growing/etching time ratio (180/30 s) case. The solely hydrogen gas feeding (C2H2 flow off) time during the initial deposition stage seems to play an important role for the variation in the CNFs formation characteristics by the cyclic modulation process.

Precursor design and engineering for low-temperature deposition of gate dielectrics for thin film transistors

2011 ◽  
Vol 1287 ◽  
Author(s):  
Anupama Mallikarjunan ◽  
Laura M Matz ◽  
Andrew D Johnson ◽  
Raymond N Vrtis ◽  
Manchao Xiao ◽  
...  
Keyword(s):  
Thin Film ◽  
Low Temperature ◽  
Thin Film Transistors ◽  
Moisture Absorption ◽  
Silicon Oxide ◽  
Chemical Vapor ◽  
Silicon Oxycarbide ◽  
Process Conditions ◽  
Structure Property ◽  
Oh Groups

ABSTRACTThe electrical and physical quality of gate and passivation dielectrics significantly impacts the device performance of thin film transistors (TFTs). The passivation dielectric also needs to act as a barrier to protect the TFT device. As low temperature TFT processing becomes a requirement for novel applications and plastic substrates, there is a need for materials innovation that enables high quality plasma enhanced chemical vapor deposition (PECVD) gate dielectric deposition. In this context, this paper discusses structure-property relationships and strategies for precursor development in silicon nitride, silicon oxycarbide (SiOC) and silicon oxide films. Experiments with passivation SiOC films demonstrate the benefit of a superior precursor (LkB-500) and standard process optimization to enable lower temperature depositions. For gate SiO2 deposition (that are used with polysilicon TFTs for example), organosilicon precursors containing different types and amounts of Si, C, O and H bonding were experimentally compared to the industry standard TEOS (tetraethoxysilane) at different process conditions and temperatures. Major differences were identified in film quality especially wet etch rate or WER (correlating to film density) and dielectric constant (k) values (correlating to moisture absorption). Gate quality SiO2 films can be deposited by choosing precursors that can minimize residual Si-OH groups and enable higher density stable moisture-free films. For e.g., the optimized precursor AP-LTO® 770 is clearly better than TEOS for low temperature PECVD depositions based on density, WER, k charge density (measured by flatband voltage or Vfb); and leakage and breakdown voltage (Vbd) measurements. The design and development of such novel precursors is a key factor to successfully enable manufacturing of advanced low temperature processed devices.

scholarly journals Catalyst-Less and Transfer-Less Synthesis of Graphene on Si(100) Using Direct Microwave Plasma Enhanced Chemical Vapor Deposition and Protective Enclosures

Materials ◽  
2020 ◽  
Vol 13 (24) ◽  
pp. 5630
Author(s):  
Rimantas Gudaitis ◽  
Algirdas Lazauskas ◽  
Šarūnas Jankauskas ◽  
Šarūnas Meškinis
Keyword(s):  
Chemical Vapor Deposition ◽  
Vapor Deposition ◽  
Gas Flow ◽  
Microwave Plasma ◽  
Lattice Mismatch ◽  
Chemical Vapor ◽  
Hydrogen Gas ◽  
Synthesis Process ◽  
Synthesis Time ◽  
Graphene Layers

In this study, graphene was synthesized on the Si(100) substrates via the use of direct microwave plasma-enhanced chemical vapor deposition (PECVD). Protective enclosures were applied to prevent excessive plasma etching of the growing graphene. The properties of synthesized graphene were investigated using Raman scattering spectroscopy and atomic force microscopy. Synthesis time, methane and hydrogen gas flow ratio, temperature, and plasma power effects were considered. The synthesized graphene exhibited n-type self-doping due to the charge transfer from Si(100). The presence of compressive stress was revealed in the synthesized graphene. It was presumed that induction of thermal stress took place during the synthesis process due to the large lattice mismatch between the growing graphene and the substrate. Importantly, it was demonstrated that continuous horizontal graphene layers can be directly grown on the Si(100) substrates if appropriate configuration of the protective enclosure is used in the microwave PECVD process.

Effects of Reaction Conditions on MoS2 Thin Film Formation Synthesized by Chemical Vapor Deposition using Organic Precursor

MRS Advances ◽  
2016 ◽  
Vol 2 (29) ◽  
pp. 1533-1538 ◽  
Author(s):  
S. Ishihara ◽  
Y. Hibino ◽  
N. Sawamoto ◽  
T. Ohashi ◽  
K. Matsuura ◽  
...  
Keyword(s):  
Thin Film ◽  
Chemical Vapor Deposition ◽  
Low Temperature ◽  
Flow Rate ◽  
Vapor Deposition ◽  
Gas Flow ◽  
Film Formation ◽  
Chemical Vapor ◽  
Gas Flow Rate ◽  
Axis Orientation

ABSTRACTMolybdenum disulfide (MoS2) thin films were fabricated by two-step chemical vapor deposition (CVD) using (t-C4H9)2S2 and the effects of temperature, gas flow rate, and atmosphere on the formation were investigated in order to achieve high-speed low-temperature MoS2 film formation. From the results of X-ray photoelectron spectroscopy (XPS) and transmission electron microscopy (TEM) investigations, it was confirmed that c-axis orientation of the pre-deposited Mo film has a significant involvement in the crystal orientation after the reaction low temperature sulfurization annealing and we successfully obtained 3 nm c-axis oriented MoS2 thin film. From the S/Mo ratios in the films, it was revealed that the sulfurization reaction proceeds faster with increase in the sulfurization temperature and the gas flow rate. Moreover, the sulfurization under the H2 atmosphere promotes decomposition reaction of (t-C4H9)2S2, which were confirmed by XPS and density functional theory (DFT) simulation.

A Low Temperature Photonic Crystal Technology for Integration with Modern CMOS Technologies

2007 ◽  
Vol 990 ◽  
Author(s):  
Khadijeh Bayat ◽  
Mahdi Farrokh Baroughi ◽  
Sujeet K. Chaudhuri ◽  
Safieddin Safavi-Naeini
Keyword(s):  
Photonic Crystal ◽  
Low Temperature ◽  
Integrated Circuits ◽  
Gas Phase ◽  
Gas Flow ◽  
Chemical Vapor ◽  
Silicon Oxynitride ◽  
Refractive Indices ◽  
Optical Integrated Circuits ◽  
Silicon Based

ABSTRACTIn this paper, low temperature amorphous silicon oxynitride (a-SixOyNz:H) thin film technology is proposed for implementation of CMOS compatible photonic crystal (PC) based optical integrated circuits (OICs). The a-SixOyNz films of different refractive indices were developed by plasma enhanced chemical vapor deposition (PECVD) technique using silane, nitrous oxide, and ammonia as gas phase precursors at 300°C. The films with refractive index between 1.43 − 1.75 were obtained by changing gas flow ratios. Such thin films can be used as cladding and core layers in photonic crystal structure.The bandgap and guiding properties of the a-SixOyNz based PCs were simulated and was shown that the a-SixOyNz:H based PC technology offers larger feature sizes than a conventional silicon based photonic crystals.

Laser-Induced Chemical Vapor Deposition of Silicon Nitride Films

1983 ◽  
Vol 29 ◽  
Author(s):  
Gary A. West ◽  
Arunava Gupta
Keyword(s):  
Silicon Nitride ◽  
Gas Flow ◽  
Silicon Oxide ◽  
Continuous Wave ◽  
Chemical Vapor ◽  
Gaseous Mixtures ◽  
Silicon Nitride Films ◽  
Film Content ◽  
Gas Flow Ratio ◽  
Laser Cvd

ABSTRACTFilms of silicon nitride have been deposited using a continuous wave CO2 laser to excite gaseous mixtures of silane and ammonia. A typical deposition rate is 150Å/min. The hydrogen film content and its dependence on the substrate deposition temperature are similar to that observed for plasma CVD silicon nitride. The CO2 laser CVD films are silicon rich with a Si/N ratio = 1.2 at a NH3/SiH4 gas flow ratio of 1000. Conformal step coverage is observed on patterned silicon oxide features.

Poly-SiGe TFTs Fabricated by Low Temperature Chemical Vapor Deposition at 450°C

2001 ◽  
Vol 686 ◽  
Author(s):  
Kousaku Shimizu ◽  
Jianjun Zhang ◽  
Jeong-woo Lee ◽  
Jun-ichi Hanna
Keyword(s):  
Thin Film ◽  
Chemical Vapor Deposition ◽  
Low Temperature ◽  
Vapor Deposition ◽  
Thin Film Transistors ◽  
Gas Flow ◽  
Chemical Vapor ◽  
Polycrystalline Materials ◽  
Si Substrates ◽  
Vapor Deposition Technique

AbstractLow temperature growth of poly-SiGe has been investigated by reactive thermal chemical vapor deposition technique, which is a newly developed technique for preparing polycrystalline materials with using redox reactions in a set of source materials, Si2H6 and GeF4.. In order to prepare high uniformity and reproducibility of Si-rich poly-SiGe, total pressure, gas flow ratio, and residence time are optimized at 450°C of substrate temperature. Through optimizing the conditions, poly-Si1−xGex (x<0.04) films have been prepared in the reproducibility more than 90% and uniformity more than 88%. Bottom gate type of n-channel thin film transistors has been fabricated in various grain size of poly-Si1−xGex on SiO2 (100nm)/Si substrates. 5-36 cm2/Vs of field effect mobility of thin film transistors (L/W = 50μm/50μm) have been achieved after hydrogenation, whose threshold voltage is around 2±0.5V, and on/off ratio is more than 104.

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