#electron beam lithography

[materialsscienceandengineering]

Ice lithography: Opportunities and challenges in 3-D nanofabrication

Nanotechnology and nanoscience are enabled by nanofabrication. Electron-beam lithography (EBL), which makes patterns down to a few nanometers, is one of the fundamental pillars of nanofabrication. In the past decade, significant progress has been made in electron-beam-based nanofabrication, such as the emerging ice lithography (IL) technology, in which ice thin-films are used as resists and patterned by a focused electron-beam. The entire process of IL nanofabrication is sustainable and streamlined because spin coating and chemical developing steps commonly required for EBL resists are made needless.

A fresh review "Ice lithography for 3-D nanofabrication" by Prof. Min Qiu at Westlake University is published in Science Bulletin. In this review, the authors present current status and future perspectives of ice lithography (IL). Different ice resists and IL instrument design are also introduced. Special emphasis is placed on advantages of IL for 3-D nanofabrication.

The IL technology was first proposed by the Nanopore group at Harvard University in 2005. Water ice is the first identified ice resist for IL, and it is still the only one positive-tone lithography resist so far. As shown in Fig.1, water ice is easily removed within the electron-beam exposure area. Organic ice condensed from simple organic molecules, such as alkanes, demonstrates a negative-resist-like capability, which means only exposed patterns remain on the substrate after heating the sample to room temperature.

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[materialsscienceandengineering]

Researchers Develop Metasurface to Manipulate Infrared Light

Optical waves propagating away from a point source typically exhibit circular (convex) wavefronts. “Like waves on a water surface when a stone is dropped,” explains Peining Li, EU Marie Sklodowska-Curie fellow at nanoGUNE and first author of the paper. The reason of this circular propagation is that the medium through which light travels is typically homogenous and isotropic i.e. uniform in all directions.

Scientists had already theoretically predicted that specifically structured surfaces can turn the wavefronts of light upside down when it propagates along them. “On such surfaces, called hyberbolic metasurfaces, the waves emitted from a point source propagate only in certain directions and with open (concave) wavefronts,” explains Javier Alfaro, PhD student at nanoGUNE and co-author of the paper. These unusual waves are called hyperbolic surface polaritons. Because they propagate only in certain directions, and with wavelengths that are much smaller than that of light in free space or standard waveguides, they could help to miniaturize optical devices for sensing and signal processing.

Now, the researchers developed such a metasurface for infrared light. It is based on boron nitride, a graphene-like 2D material, and was selected because of its capability to manipulate infrared light on extremely small length scales, which could be applied for the development of miniaturized chemical sensors or for heat management in nanoscale optoelectronic devices. On the other hand, the researchers succeeded to directly observe the concave wavefronts with a special optical microscope, which have been elusive so far.

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[materialsscienceandengineering]

Researchers create ultrafast tunable semiconductor metamaterial

An international team of researchers from Moscow State University (Russia), Sandia National Laboratories (U.S.), and Friedrich-Schiller University (Germany) have devised an ultrafast tunable metamaterial based on gallium arsenide nanoparticles. Their study was published in Nature Communications. The new optical metamaterial paves the way to ultrafast information transfer on the nanoscale.

Optical metamaterials are man-made media that acquire unusual optical properties due to nanostructuring. For almost 20 years, researchers have designed many metamaterial-based devices, including those hiding objects to those sensitive to minute concentrations of substances. However, upon fabrication, metamaterial properties remain fixed. The team came up with a way to turn metamaterials "on" and "off," and do it very quickly—more than 100 billion times per second.

Researchers fabricated the metamaterial from a thin gallium arsenide film by electron-beam lithography with subsequent plasma etching. The material consists of an array of semiconductor nanoparticles, which can resonantly concentrate and "hold" light at the nanoscale. In other words, when the light illuminates the metamaterial, it is "trapped" inside the nanoparticles and interacts more efficiently with them.

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[materialsscienceandengineering]

Scientists set record resolution for drawing at the one-nanometer length scale

An electron microscope-based lithography system for patterning materials at sizes as small as a single nanometer could be used to create and study materials with new properties

The ability to pattern materials at ever-smaller sizes -- using electron-beam lithography (EBL), in which an electron-sensitive material is exposed to a focused beam of electrons, as a primary method -- is driving advances in nanotechnology. When the feature size of materials is reduced from the macroscale to the nanoscale, individual atoms and molecules can be manipulated to dramatically alter material properties, such as color, chemical reactivity, electrical conductivity, and light interactions.

In the ongoing quest to pattern materials with ever-smaller feature sizes, scientists at the Center for Functional Nanomaterials (CFN) -- a U.S. Department of Energy (DOE) Office of Science User Facility at Brookhaven National Laboratory -- have recently set a new record. Performing EBL with a scanning transmission electron microscope (STEM), they have patterned thin films of the polymer poly(methyl methacrylate), or PMMA, with individual features as small as one nanometer (nm), and with a spacing between features of 11 nm, yielding an areal density of nearly one trillion features per square centimeter. These record achievements are published in the April 18 online edition of Nano Letters.

"Our goal at CFN is to study how the optical, electrical, thermal, and other properties of materials change as their feature sizes get smaller," said lead author Vitor Manfrinato, a research associate in CFN's electron microscopy group who began the project as a CFN user while completing his doctoral work at MIT. "Until now, patterning materials at a single nanometer has not been possible in a controllable and efficient way."

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[pddparthi]

Unraveling the Complexities of Electron Beam Lithography: A Comprehensive Guide

Electron beam lithography (EBL) stands at the forefront of nanotechnology, wielding the power of focused electron beams to sculpt intricate patterns on surfaces with astonishing precision. This guide delves into the complexities of EBL, unveiling its core principles, groundbreaking advancements, and diverse applications, solidifying its position as a cornerstone in the realm of…

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[dischemincusa]

How Is Electron Beam Lithography Used In Nanotechnology?

Electron beam lithography is a process of creating exact patterns on a surface by firing a narrowly focused beam of electrons at it. This technique is used in nanotechnology to create the possible minor structures, often less than one-millionth of a meter in size.

[discheminc0]

Electron beam lithography

SurPass is a waterborne agent designed to promote adhesion and improve overall coating quality on a broad range of substrate materials used in photon and electron beam lithography. https://confengine.com/user/discheminc

[discheminc0]

Guide about Electron Beam Lithography

Electron beam lithography. What is this, and who should have this machine? This is a question that we are getting a lot. You need to make sure that you are getting all the information about the beam to understand what it is and why this is something businesses need. https://discheminc.com/guide-about-electron-beam-lithography/