Search results for "lithography"

Influence of the Number of Nanoparticles on the Enhancement Properties of Surface-Enhanced Raman Scattering Active Area: Sensitivity versus Repeatabi…

2011

In the present work, the combination of chemical immobilization with electron beam lithography enables the production of sensitive and reproducible SERS-active areas composed of stochastic arrangements of gold nanoparticles. The number of nanoparticles was varied from 2 to 500. Thereby a systematic analysis of these SERS-active areas allows us to study SERS efficiency as a function of the number of nanoparticles. We found that the experimental parameters are critical, in particular the size of the SERS-active area must be comparable to the effective area of excitation to obtained reproducible SERS measurements. The sensitivity has also been studied by deducing the number of NPs that generat…

Inorganic Materials and Ionic Liquids: Large-scale Nanopatterning of Single Proteins used as Carriers of Magnetic Nanoparticles (Adv. Mater. 5/2010)

2010

Nano-lithography using a resist, patterned by electron exposure in an AFM configuration

1996

We have used a metallised force microscope tip to apply a voltage and thereby expose a very thin resist film. It is possible to image the film surface before, during and after the exposure, without interference with the process. Uniform resist films as thin as 10 nm are fabricated using the Langmuir-Blodgett technique. To orient the defined pattern and to make electrical connections a special larger scale alignment structure is first defined by conventional electron beam lithography, either directly in the Langmuir-Blodgett resist film or in a complete first process with a separate resist system. The results from the one resist process gave conducting 50 nm lines in a 60 A thick aluminium f…

Electrogeneration of Diiodoaurate in Dimethylsulfoxide on Gold Substrate and Localized Patterning

2016

International audience; A localized etching of gold surface by scanning electrochemical microscope technique is presented where a dimethylsulfoxide-based electrolyte charged with iodine is used. The electrogenerated triiodide ion at the platinum ultramicroelectrode tip (feedback mode) acts as an oxidant for gold surface. The effects of electrode diameter and the bias time have been investigated. The approach curve method was used to hold the electrode tip close to the gold surface. A scanning electron microscope is used to observe the etched gold surfaces where disk-shaped dots are generated. The diameter of these holes depends directly on the Pt electrode diameter and the bias time.

Ag and Au/DNQ-novolac nanocomposites patternable by ultraviolet lithography: a fast route to plasmonic sensor microfabrication

2010

In this work we report on a method to synthesize Ag–Au nanoparticles/polymer nanocomposite patterns by UV lithography. The photoresists are based on DNQ-novolac as the polymer matrix, and Ag(I) and Au(III) salts as the nanoparticle precursors. After UV lithography, silver and gold nanoparticles are in situ synthesized inside the polymer patterns during a post bake. The resulting structured nanocomposite shows a characteristic absorbance spectrum related to the plasmon frequency of the synthesized noble metal NPs. This method represents a fast, simple and low-cost approach to the formation of extended polymer patterns with embedded silver or gold NPs. Moreover, it is a mechanism to position …

Cover Picture: Nanoscale Deposition of Single-Molecule Magnets onto SiO2 Patterns (Adv. Mater. 2/2007)

2007

The cover shows a schematic of scanning probe nanolithography based on the spatial confinement of an oxidation reaction within a water meniscus, and its application for fabricating ordered arrays of cationic Mn12 single-molecule magnets. Romero, Coronado, Garcia, and co-workers report on p. 291 that electrostatic interactions between the molecules and trapped charges within the nanodots drive the positioning of the molecules at the nanoscale.

Advances in SPMs for Investigation and Modification of Solid-Supported Monolayers

2007

Improvement in nanotechnology research has been strongly driven by the advancement that nanoscale characterization and manipulation tools made from the beginning. Solidsupported monolayers (SSMs) represent one of the most important systems in nanotechnology. High-quality SSMs may be fabricated at low cost by solution processes employing techniques like self-assembly and Langmuir–Blodgett methods. In the last decade, advances in scanning probe methods provided more and more efficient tools able both to probe with largely improved resolution the morphological features of SSMs and to modify selectively their functional groups. The modified self-assembled monolayers can be used as nanotemplates…

DNA-Assisted Molecular Lithography

2018

During the past decade, DNA origami has become a popular method to build custom two- (2D) and three-dimensional (3D) DNA nanostructures. These programmable structures could further serve as templates for accurate nanoscale patterning, and therefore they could find uses in various biotechnological applications. However, to transfer the spatial information of DNA origami to metal nanostructures has been limited to either direct nanoparticle-based patterning or chemical growth of metallic seed particles that are attached to the DNA objects. Here, we present an alternative way by combining DNA origami with conventional lithography techniques. With this DNA-assisted lithography (DALI) method, we…

Subwavelength mapping of surface photonic states

2003

We show that the spectral tailoring of optical local density of states (LDOS) may be achieved by lithographically designed nanostructures and that the subwavelength mapping of the spectral variation of the optical LDOS is feasible by varying the driving frequency of the effective dipole used in an illumination mode scanning near-field optical microscope.

Mapping the 3D-surface strain field of patterned tensile stainless steels using atomic force microscopy.

2005

Abstract The quantification of microstructural strains at the surface of materials is of major importance for understanding the reactivity of solids. The present paper aims at demonstrating the potentialities of the atomic force microscopy (AFM) for mapping the three-dimensional surface strain field on patterned tensile specimens. Electron beam (e-beam) lithography has been used to deposit 16×16 arrays of gold-squared pads. Monitoring the evolution of such a pattern under applied strain allows to quantify the triaxial strains both at the micro-(plastic) domain and nanoscale (elastic) domain vs. applied strain. The proposed method was applied to stainless steels after 4.5% plastic strain.