Controlled deposition of carbon nanotubes on a patterned substrate
Introduction
Carbon nanotubes (NTs), discovered in 1991 [1], have open a promising way in nanotechnology [2], [3], [4], [5], [6], [7], [8], [9], [10], [11], [12], [13], [14], [15], [16], [17]. For electronic applications, NTs provide insulating, semiconducting or truly conducting nanoscale wires [3], [4], [5], [6], [7], [8], and components such as a junction [9], [10], [11] and a field-effect transistor [12], [13], [14], [15] have even been demonstrated. For nanomechanics, NTs provide fibres with unprecedented mechanical properties that can be used to fabricate nanotools [16], [17].
However, the fabrication of all kinds of NT-based devices is severely hindered by the lack of a simple and reliable process to deposit NTs in a controlled way. Up to now, all the demonstrated NT electrical devices have been nanofabricated either by randomly depositing NTs on a multi-electrode array or by patterning contacts onto randomly deposited NTs, after their observation [3], [4], [5], [6], [7], [9], [10], [11], [12], [13], [14]. Although alternative methods such as direct NT growth on catalytic templates [18], [19] or between patterned metallic pads [15] have been demonstrated, the lack of a generic solution for the controlled deposition of NTs at given locations of a surface is a major bottleneck. Such a process was recently proposed by Liu et al. [20], relying on a local chemical functionalization of the surface of the substrate. In the present work, we demonstrate another method for achieving this control. This method, described in Fig. 1, is based on the electrostatic anchoring of surfactant covered NTs on amino-silane functionalized surfaces [21]: first, a reactive amino-silane template is prepared using chemical vapour deposition of silane molecules through a PMMA mask patterned by conventional electron-beam lithography. Surfactant covered NTs are then selectively deposited on the template. Finally, the PMMA mask is lifted-off, leaving the tubes on the template. In the following, we describe the method in detail, and we discuss in particular the deposition yield and the alignment quality.
Section snippets
Experimental
The SWNT raw material, produced by the arc discharge method, was purchased as AP grade from CarboLex (Lexington, USA). Surfactant stabilized tube dispersions were prepared by sonication of raw material in an aqueous 1 wt% sodium dodecylsulphate (SDS) solution. After some macroscopic particles had settled (over 10 min), the dark dispersions were loaded into the chromatographic column for purification as described in Ref. [22].
Oxidized silicon substrates (oxide thickness 300 nm) were cleaned as
Results and discussion
As a first step, we investigated the fabrication of a patterned self-assembled monolayer (SAM) of silane based molecules. Several techniques have been described in the literature for the patterning of a SAM of trichloro- or trialkoxy-silane on silica. Most use direct writing in the SAM with either photolithography, ion-beam, e-beam, atomic-beam or scanning probe microscopy lithography [23], [24], [25], [26], [27], [28]. Some use a SAM as resist to etch the underlying substrate or insert another
Conclusion
In this work, we designed a new simple and efficient technique to prepare patterned aminosilane monolayers forming a template suitable for the deposition of SDS-covered NTs at predefined locations. In the course of this work, we showed how gas-phase silane deposition could be controlled down to the monolayer level and a lateral extension of 50 nm, and we demonstrated a simple way for directly measuring the thickness of the silane layer. Using such silanized patterns, we deposited isolated NTs
Acknowledgements
The authors are grateful to S. Palacin and V. Huc for useful discussions and to O. Araspin and P. Orfila for their help with the lithography. This work was supported in part by the EU NANOMOL IST-1999-12603 project2.
References (36)
- et al.
Chem. Phys. Lett.
(1999) Nature
(1991)- et al.
Adv. Mater.
(1997) - et al.
Phys. Rev. Lett.
(1992) - et al.
Phys. Rev. Lett.
(1992) - et al.
Science of Fullerenes and Carbon Nanotubes
(1996) - et al.
Nature
(1997) - et al.
Science
(1997) - et al.
Science
(1997) - et al.
Phys. Rev. Lett.
(1999)
Nature
Science
Nature
Appl. Phys. Lett.
Appl. Phys. Lett.
Appl. Phys. Lett.
Nature
Science
Cited by (123)
Detection of a secreted protein biomarker for citrus Huanglongbing using a single-walled carbon nanotubes-based chemiresistive biosensor
2020, Biosensors and BioelectronicsCitation Excerpt :Five μL of SWNT solution was drop-casted onto the patterned APTES region and the droplet was allowed to dry in air overnight. The anionic surfactant molecules, which are physisorbed to the SWNTs, are electrostatically attracted to the amino groups of the APTES covered surface, which consequently anchors the SWNTs onto the APTES-functionalized SiO2 surface (Choi et al., 2000; Liu et al., 1999; Sarkar and Daniels-Race, 2013). Washing the device with distilled water removes excess unbound and weakly bound SWNTs and excess surfactant molecules from the sensor surface.
Directed Assembly of Carbon Nanotubes
2017, Comprehensive Supramolecular Chemistry IIImmobilization of streptavidin on 4H-SiC for biosensor development
2012, Applied Surface ScienceNanoscale Patterning of Carbon Nanotubes: Techniques, Applications, and Future
2021, Advanced ScienceLatest Research Progress of Horizontal Alignment of Single-walled Carbon Nanotubes Based on Solution Method
2019, Cailiao Daobao/Materials Review
- 1
Present address: MCP-NM, IMEC vzw, Kapeldreef 75, B-3001 Leuven, Belgium.