Nanolithography and Nanochemistry: Probe‐Related Patterning Techniques and Chemical Modification for Nanometer‐Sized Devices

Wouters, D Daan; Schubert, Ulrich S.

doi:10.1002/anie.200300609

Cited by 306 publications

(190 citation statements)

References 133 publications

(232 reference statements)

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“…11 Here we report results using in-situ force microscopy to investigate the dynamics of virus organization at nanoscale chemical templates fabricated using scanned probe nanolithography (SPN). [12][13][14] By varying virus flux and inter-viral potential and measuring the time dependence of pattern morphology, we show that the physics of directed macromolecular assembly can be understood by combining principles governing small molecule epitaxy with those that drive colloidal condensation in confined systems.…”

Section: Introductionmentioning

confidence: 99%

Physical Controls on Directed Virus Assembly at Nanoscale Chemical Templates

et al. 2006

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Viruses are attractive building blocks for nanoscale heterostructures, but little is understood about the physical principles governing their directed assembly. In-situ force microscopy was used to investigate organization of Cowpea Mosaic Virus engineered to bind specifically and reversibly at nanoscale chemical templates with sub-30nm features. Morphological evolution and assembly kinetics were measured as virus flux and inter-viral potential were varied. The resulting morphologies were similar to those of atomic-scale epitaxial systems, but the underlying thermodynamics was analogous to that of colloidal systems in confined geometries. The 1D templates biased the location of initial cluster formation, introduced asymmetric sticking probabilities, and drove 1D and 2D condensation at subcritical volume fractions. The growth kinetics followed a t 1/2 law controlled by the slow diffusion of viruses. The lateral expansion of virus clusters that initially form on the 1D templates following introduction of polyethylene glycol (PEG) into the solution suggests a significant role for weak

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Section: Introductionmentioning

confidence: 99%

Physical Controls on Directed Virus Assembly at Nanoscale Chemical Templates

et al. 2006

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“…Atomic force microscopy ͑AFM͒ oxidation nanolithography is a robust and flexible tip-based nanofabrication method [1][2][3][4][5] that is used to fabricate high resolution patterns and nanoscale devices. Thus, templates to build molecular architectures, 6,7 resist masks, 8 nanomechanical resonators, 9,10 or several nanoelectronic devices and transistors [11][12][13][14] have been fabricated by local oxidation.…”

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confidence: 99%

Nanoscale space charge generation in local oxidation nanolithography

Chiesa¹,

García²

2010

Applied Physics Letters

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We have measured the surface potential and the space charge generated during the first stages of atomic force microscopy field-induced oxidation. Space charge densities are about 10 17 cm −3 for oxidation times below 10 ms. In a dry atmosphere, the surface potential is negative. However, in humid air the surface potential could be either positive or negative. This effect is attributed to a screening effect of the water molecules. These results explain and support the use of local oxidation patterns as templates for building molecular architectures. They also establish the space charge build up as an intrinsic feature in local oxidation experiments. © 2010 American Institute of Physics. ͓doi:10.1063/1.3459976͔Atomic force microscopy ͑AFM͒ oxidation nanolithography is a robust and flexible tip-based nanofabrication method [1][2][3][4][5] that is used to fabricate high resolution patterns and nanoscale devices. Thus, templates to build molecular architectures, 6,7 resist masks, 8 nanomechanical resonators, 9,10 or several nanoelectronic devices and transistors [11][12][13][14] have been fabricated by local oxidation. In AFM oxidation, the tip is used as a cathode and the water meniscus formed between the tip and the surface is the source of the oxyanions species. 15 The strong localization of the electrical field lines near the tip apex and the lateral confinement of the oxyanions species within the liquid meniscus give rise to a nanometer-size oxide dot. [16][17][18][19][20] The kinetics of the oxidation process is influenced by the generation of a space charge. [21][22][23] The model by Dagata et al. 21,24 considers two competing mechanisms, a fast oxidation process that applies to the initial stages ͑below 1 s͒ and a slower, indirect process that applies for longer oxidation times and involves space charge. Dubois and Bubendorff's model is based on a charge trapping-detrapping mechanism. 23 Most of the AFM oxidation nanolithography applications involve oxidation times below 1 s. Recently, local oxide patterns have been used as high resolution templates for the growth of functional materials such as protein carriers 7 or single molecule magnets. 25 The underlying mechanism behind the organization of molecular architectures is based on the electrostatic interactions between the charged or polarized molecules and the space charges trapped inside the local oxides. However, there is no experimental evidence that supports the existence of space charges for short oxidation times. In addition, the sign of the charge has not been measured.Here, we perform Kelvin probe force microscopy ͑KPFM͒ experiments to determine the space charge sign and density. The measurements establish the presence of a space charge build up during the earlier stages of the oxidation process ͑below 10 ms͒. The sign of the apparent space charge depends on the relative humidity inside the chamber where the KPFM measurements are performed. In dry conditions ͑N 2 gas environment͒ the observed charge is always negative. However, in the presence of wat...

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“…Nevertheless, low throughput serial processing or technical hardship arising from direct mechanical contact does not allow for a mass-producible process. [15][16][17] An alternative method is selfassembly, where the spontaneous organization of nanoscale building blocks allows for the large-scale, parallel production of periodic nanostructures. A representative example is nanosphere lithography (NSL), which utilizes a self-assembled hexagonal nanosphere array as a lithographic mask.…”

Section: 14mentioning

confidence: 99%

A plasmonic biosensor array by block copolymer lithography

et al. 2010

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Highly uniform and dense, hexagonal noble metal nanoparticle arrays were achieved on large-area transparent glass substrates via scalable, parallel processing of block copolymer lithography. Exploring their localized surface plasmon resonance (LSPR) characteristics revealed that the Ag nanoparticle array displayed a UV-vis absorbance spectrum sufficiently narrow and intense for biosensing application. A highly-sensitive, label-free detection of prostate cancer specific antibody (anti-PSA) with sub-ng ml À1 level detection limit (0.1$1 ng ml À1) has been accomplished with the plasmonic nanostructure. Our approach offers a valuable route to a low-cost, manufacture-scale production of plasmonic nanostructures, potentially useful for various photonic and optoelectronic devices.

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Nanolithography and Nanochemistry: Probe‐Related Patterning Techniques and Chemical Modification for Nanometer‐Sized Devices

Cited by 306 publications

References 133 publications

Physical Controls on Directed Virus Assembly at Nanoscale Chemical Templates

Physical Controls on Directed Virus Assembly at Nanoscale Chemical Templates

Nanoscale space charge generation in local oxidation nanolithography

A plasmonic biosensor array by block copolymer lithography

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