scholarly journals Low Temperature Synthesis of High-Density Carbon Nanotubes on Insulating Substrate

Nanomaterials ◽  
2019 ◽  
Vol 9 (3) ◽  
pp. 473 ◽  
Author(s):  
Ying Xiao ◽  
Zubair Ahmed ◽  
Zichao Ma ◽  
Changjian Zhou ◽  
Lining Zhang ◽  
...  
Keyword(s):  
Carbon Nanotubes ◽  
Low Temperature ◽  
High Surface ◽  
Chemical Vapor ◽  
Synthesis Temperature ◽  
Catalyst Design ◽  
High Density ◽  
Oxide Semiconductor ◽  
Multi Wall Carbon Nanotubes ◽  
Vertically Aligned

A method to synthesize high-density, vertically-aligned, multi-wall carbon nanotubes (MWCNTs) on an insulating substrate at low temperature using a complementary metal–oxide–semiconductor (CMOS) compatible process is presented. Two factors are identified to be important in the carbon nanotube (CNT) growth, which are the catalyst design and the substrate material. By using a Ni–Al–Ni multilayer catalyst film and a ZrO2 substrate, vertically-aligned CNTs can be synthesized at 340 °C using plasma-enhanced chemical vapor deposition (PECVD). Both the quality and density of the CNTs can be enhanced by increasing the synthesis temperature. The function of the aluminum interlayer in reducing the activation energy of the CNT formation is studied. The nanoparticle sintering and quick accumulation of amorphous carbon covering the catalyst can prematurely stop CNT synthesis. Both effects can be suppressed by using a substrate with a high surface energy such as ZrO2.

scholarly journals Synthesis of Vertical Carbon Nanotube Interconnect Structures Using CMOS-Compatible Catalysts

Nanomaterials ◽  
2020 ◽  
Vol 10 (10) ◽  
pp. 1918
Author(s):  
Zichao Ma ◽  
Shaolin Zhou ◽  
Changjian Zhou ◽  
Ying Xiao ◽  
Suwen Li ◽  
...  
Keyword(s):  
Low Temperature ◽  
Complementary Metal Oxide Semiconductor ◽  
Synthesis Temperature ◽  
Catalyst Design ◽  
High Density ◽  
Oxide Semiconductor ◽  
Catalyst Film ◽  
Cnt Arrays ◽  
Cmos Compatible ◽  
Catalyst Nanoparticle

Synthesis of the vertically aligned carbon nanotubes (CNTs) using complementary metal-oxide-semiconductor (CMOS)-compatible methods is essential to integrate the CNT contact and interconnect to nanoscale devices and ultra-dense integrated nanoelectronics. However, the synthesis of high-density CNT array at low-temperature remains a challenging task. The advances in the low-temperature synthesis of high-density vertical CNT structures using CMOS-compatible methods are reviewed. Primarily, recent works on theoretical simulations and experimental characterizations of CNT growth emphasized the critical roles of catalyst design in reducing synthesis temperature and increasing CNT density. In particular, the approach of using multilayer catalyst film to generate the alloyed catalyst nanoparticle was found competent to improve the active catalyst nanoparticle formation and reduce the CNT growth temperature. With the multilayer catalyst, CNT arrays were directly grown on metals, oxides, and 2D materials. Moreover, the relations among the catalyst film thickness, CNT diameter, and wall number were surveyed, which provided potential strategies to control the tube density and the wall density of synthesized CNT array.

Synthesis of Vertically Aligned Carbon Nanotubes by dc PECVD

2006 ◽  
Vol 326-328 ◽  
pp. 333-336
Author(s):  
Yun Young Bang ◽  
Tae Jin Je ◽  
Kyung Hyun Whang ◽  
Won Seok Chang
Keyword(s):  
Carbon Nanotubes ◽  
Chemical Vapor Deposition ◽  
Carbon Source ◽  
Vapor Deposition ◽  
Chemical Vapor ◽  
Catalyst Layer ◽  
Metal Catalyst ◽  
Synthesis Methods ◽  
Multi Wall Carbon Nanotubes ◽  
Vertically Aligned

Chemical vapor deposition (CVD) is one of the various synthesis methods that have been employed for CNT growth. In particular, Ren et al reported that large areas of vertically aligned multi-wall carbon nanotubes could be grown using plasma enhanced chemical vapor deposition (PECVD). In the present study, we synthesized aligned CNT arrays using a direct current (dc) PECVD system. The synthesis of CNTs requires a metal catalyst layer, etchant gas, and a carbon source. In this study, the substrate consisted of Si wafers with 10, 30, and 50 nm Ni-sputtered film. Ammonia (NH3) and acetylene (C2H2) were used as the etchant gases and carbon source, respectively. NH3 pretreatment was processed using a flow rate of 180 sccm for 10 min. CNTs were grown on pretreated substrates at 30% C2H2:NH3 flow ratios for 10 min. Carbon nanotubes with diameters ranging from 60 to 80 nanometers and lengths of about 2.7 μm were obtained. Vertical alignment of the carbon nanotubes was observed by FE-SEM.

In-situ Plasma Diagnosis of Chemical Species in Microwave Plasma-assisted Chemical Vapor Deposition for the Growth of Carbon Nanotubes Using CH4/H2/NH3 Gases

2000 ◽  
Vol 621 ◽  
Author(s):  
Y.S. Woo ◽  
I.T. Han ◽  
N.S. Lee ◽  
J.E. Jung ◽  
D.Y. Jeon ◽  
...  
Keyword(s):  
Carbon Nanotubes ◽  
Chemical Vapor Deposition ◽  
Low Temperature ◽  
Vapor Deposition ◽  
Microwave Plasma ◽  
Carbon Sources ◽  
Chemical Species ◽  
Chemical Vapor ◽  
Optical Emission ◽  
Multi Wall Carbon Nanotubes

ABSTRACTSynthesis of multi-wall carbon nanotubes (MWNTs) was attempted by microwave plasma enhanced chemical vapor deposition using CH4/H2/NH3 gases on Ni/Cr-coated glass at low temperature. The synthesis was investigated by optical emission spectroscopy and quadrupole mass spectroscopy. It was observed that MWNTs could be grown within a very restrictive range of gas compositions. An addition of a small amount of NH3 resulted in a decrease of C2H2, which can be used to estimate the amount of carbon sources in plasma for the growth of MWNTs, and an increase of CN and Hα radicals acting as etching species of carbon phases. These results show that carbon nanotubes can be grown only under an appropriate condition that the growing process surpasses the etching process. The optimum C2H2 /Hα ratio in a gas mixture was found to be between 1 and 3 for the MWNT growth at low temperature.

The Effect of Precursor Vaporization Temperature on the Growth of Vertically Aligned Carbon Nanotubes Using Palm Oil

2011 ◽  
Vol 312-315 ◽  
pp. 906-911 ◽  
Author(s):  
Abu Bakar Suriani ◽  
Salina Muhamad ◽  
Puteri Sarah Mohamad Saad ◽  
Syazwan Afif Mohd Zobir ◽  
Roslan Md Nor ◽  
...  
Keyword(s):  
Carbon Nanotubes ◽  
Palm Oil ◽  
Chemical Vapor ◽  
Synthesis Temperature ◽  
Lower Growth ◽  
Vaporization Temperature ◽  
Vapor Deposition Technique ◽  
Temperature Ranges ◽  
Lower Growth Rate ◽  
Vertically Aligned

Carbon nanotubes (CNTs) were fabricated from palm oil using the thermal chemical vapor deposition technique utilizing a two furnace system. The effect of precursor vaporization temperature of the first furnace, in the range of 300-600°C was systematically studied with the synthesis temperature (second furnace) fixed at 750°C for a total time of 30 min. The samples were characterized using field emission scanning electron microscopy and micro-Raman spectroscopy. CNTs of various packing densities and diameters were synthesized with the varying precursor vaporization temperature. Based on micro-Raman measurements nanotube defect level and the presence of SWCNT were dependent on the vaporization temperature. Vertically aligned CNTs (VACNTs) were found to grow within the vaporization temperature range of 400-500°C, with well graphitized and higher yield obtained at 450°C with excellent lateral alignment, uniform nanotubes diameter (~15 nm), orientation and distribution within the CNT bundles. At vaporization temperatures of 300-350°C and 500-600°C, lower growth rate, bigger nanotubes diameter and higher ID/IG ratio were observed which indicated lower nanotubes quality that produced at both temperature ranges.

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