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51.
52.
Govindhan Dhanaraj Yi Chen Hui Chen Dang Cai Hui Zhang Michael Dudley 《Journal of Electronic Materials》2007,36(4):332-339
A chemical vapor deposition (CVD) system was designed and fabricated in our laboratory and SiC homo-epitaxial layers were
grown in the CVD process using silicon tetrachloride and propane precursors with hydrogen as a carrier gas. The temperature
field was generated using numerical modeling. Gas flow rates, temperature field, and the gradients are found to influence
the growth rates of the epitaxial layers. Growth rates were found to increase as the temperature increased at high carrier
gas flow rate, while at lower carrier gas flow rate, growth rates were observed to decrease as the temperature increased.
Based on the equilibrium model, “thermodynamically controlled growth” accounts for the growth rate reduction. The grown epitaxial
layers were characterized using various techniques. Reduction in the threading screw dislocation (SD) density in the epilayers
was observed. Suitable models were developed for explaining the reduction in the SD density as well as the conversion of basal
plane dislocations (BPDs) into threading edge dislocations (TEDs). 相似文献
53.
F. Le Normand C.S. Cojocaru O. Ersen L. Gangloff R. Alexandrescu I. Morjan 《Applied Surface Science》2007,254(4):1058-1066
Iron-based nanoparticles are prepared by a laser-induced chemical vapor deposition (CVD) process. They are characterized as body-centered Fe and Fe2O3 (maghemite/magnetite) particles with sizes ≤5 and 10 nm, respectively. The Fe particles are embedded in a protective carbon matrix. Both kind of particles are dispersed by spin-coating on SiO2/Si(1 0 0) flat substrates. They are used as catalyst to grow carbon nanotubes by a plasma- and filaments-assisted catalytic CVD process (PE-HF-CCVD). Vertically oriented and thin carbon nanotubes (CNTs) were grown with few differences between the two samples, except the diameter in relation to the initial size of the iron particles, and the density. The electron field emission of these samples exhibit quite interesting behavior with a low turn-on voltage at around 1 V/μm. 相似文献
54.
通过实验测量和理论分析, 从载流子动力学角度研究了用于脉冲辐射探测的CVD金刚石薄膜探测器的适用结构、电荷收集效率和时间响应性能. 结果表明, CVD金刚石薄膜可以制成均匀型结构的探测器; 薄膜中的缺陷会降低探测器的电荷收集效率, 探测器的电荷收集效率随场强增大而增大直至饱和. 已研制的CVD金刚石探测器电荷收集时间可达719ps, 在2.5V/μm场强下达到饱和, 电荷收集效率
达60.5%; 晶格散射是影响探测器时间响应的主要因素, 选用大晶粒甚至单晶金刚石薄膜可以提高探测器时间响应. 相似文献
55.
Interconnections between semiconductor devices in integrated circuits continue to present difficult problems in the tradeoffs
between RC time constants, production worthiness, reliability, structural complexity, and compactibility for any single technology.
A process and structure has been demonstrated for integrated circuit interconnections which uses a conformai tungsten layer
deposited by chemical vapor deposition to provide step coverage into via holes of variable height. The film is then patterned
with a via interconnect pattern designed for liftoff processing, layers of chromium copper and chromium are then depositedinsitu on the wafers by way of evaporation. The undesired material is lifted off in a solvent process and the resulting metal pattern
is used as the mask for the reactive ion etching of CVD tungsten. This combination of materials and process allows for high
conductivity reliable interconnections with negligable step coverage problems. Processing and test information will be presented
in the paper. 相似文献
56.
Monomeric tungsten oxo‐aminoalkoxides W(O)(OPri)3(L) [L = O(CH2)nNMe2; n = 2 (dmae, 1) and 3 (dmap, 2 )] were synthesized by alcohol exchange with [W(O)(OPri)4]2 and characterized spectroscopically. 1, 2 and [W(O)(OPri)4]2 were used as precursors for the aerosol‐assisted chemical vapour deposition of WO3 thin films, which were characterized by glancing angle X‐ray diffraction, SEM and transmission‐reflectance measurements. Copyright © 2008 John Wiley & Sons, Ltd. 相似文献
57.
Single‐source organometallic precursors based on a number of homometallic clusters as well as heterometallic cluster RuOs3(CO)13(µ‐H)2 have been used for the chemical vapor deposition of osmium films and osmium–ruthenium alloy films, respectively. Copyright © 2009 John Wiley & Sons, Ltd. 相似文献
58.
59.
Jagdeep S. Sagu K.G. Upul Wijayantha Paul Holland Mallika Bohm Siva Bohm Tapan Kumar Rout Hemaka Bandulasena 《Crystal Research and Technology》2016,51(8):466-474
Carbon emissions from industrial sources are of major global concern, especially contributions from the steel manufacturing process which accounts for the majority of emissions. Typical blast furnace gases consist of CO2 (20‐25%), CO (20‐25%), H2 (3‐5%) and N2 (40‐50%) and trace amounts of other gases. It is demonstrated that gas mixtures with these compositions can be used at atmospheric pressure to grow carbon nanotubes (CNTs) by chemical vapor deposition (CVD) on to steel substrates, which act as catalysts for CNT growth. Computational modelling was used to investigate the CNT growth conditions inside the CVD chamber. The results show that industrial waste pollutant gases can be used to manufacture materials with significant commercial value, in this case CNTs. 相似文献
60.
Mahrokh Elyassi Alimorad Rashidi Mohammad Reza Hantehzadeh Seyed Mohammad Elahi 《Surface and interface analysis : SIA》2017,49(4):230-237
In this study, different types of graphene were synthesized to investigate hydrogen adsorption capacity at different pressures (0–34 bar) at room temperature (298 K). Graphene and nanoporous graphene were prepared by Chemical Vapor Deposition (CVD) method, using methane as a carbon source at a temperature of 900 °C over copper plates and nickel oxide nanocatalyst. The nickel oxide nanocatalyst was prepared by sol–gel method, whereas graphene oxide was prepared through modified Hummer's method. The products were characterized by X‐ray diffraction, field emission‐scanning electron microscopy, energy dispersive spectroscopy, transmission electron microscopy, Fourier transform infrared spectroscopy, Brunauer–Emmett–Teller and Raman spectroscopy. The adsorption of hydrogen was done by volumetric method. High adsorption capacity was achieved in nanoporous graphene because of its high pore volume (2.11 cm3/g) and large specific surface area (850 m2/g). Hydrogen adsorption values for nanoporous graphene, graphene and graphene oxide were determined as 2.56, 1.70 and 0.74 wt%, respectively. In addition, the hydrogen adsorption of graphene nanostructures fitted nicely to the selected two‐parameter and three‐parameter adsorption isotherm models. The adsorption isotherm model coefficients have been found for a 0–34 bar pressure range. The parameter values for all adsorbents showed proper conformity to the model and experimental data. Copyright © 2016 John Wiley & Sons, Ltd. 相似文献