E-beam lithography for micro-/nanofabrication (original) (raw)

A simple electron-beam lithography system

Ultramicroscopy, 2005

A large number of applications of electron-beam lithography (EBL) systems in nanotechnology have been demonstrated in recent years. In this paper we present a simple and general-purpose EBL system constructed by insertion of an electrostatic deflector plate system at the electron-beam exit of the column of a scanning electron microscope (SEM). The system can easily be mounted on most standard SEM systems. The tested setup allows an area of up to about 50 Â 50 mm to be scanned, if the upper limit for acceptable reduction of the SEM resolution is set to 10 nm. We demonstrate how the EBL system can be used to write three-dimensional nanostructures by electron-beam deposition. r

High-energy Electron Beam Lithography for Nanoscale Fabrication

Lithography, 2010

Lithography 242 substrates. The electron scattering process depends greatly on incident electron energy and resist/substrate properties and is a very complex issue; thus the resultant energy-intensity distribution in the resist has to be calculated using Monte Carlo simulation. The calculated distribution is of Gaussian shape, and the contribution of secondary-electron exposure is exponentially suppressed with increased incident beam energy. Due to the long penetration depth in the resist, high-energy EBL allows for the exposure of very thick resists, which are useful for forming nanostructures with large height-to-width ratios. In multi-layer resists of different exposure sensitivities, the linewidth of each layer can be controlled separately by adjusting the development time and by using different developers after a single e-beam exposure. It will be shown that even after many development steps; the linewidth in the top layer remains unchanged. Precise control of the lower layers' linewidths makes the fabrication of sophisticated three-dimensional (3D) structures possible. In this chapter, we will first give an introduction to the state-of-the-art high-energy EBL technique. This will be followed by discussions on electron-optics, Monte-Carlo calculations of energy-intensity distribution, resist profile engineering, and mix-and-match techniques. Finally, we will give some examples to illustrate fabrications of nanoscale electronics and 3D structures, and discuss issues that have to be taken into account when using a 100keV EBL system.

Direct low-energy electron beam nanolithography

Surface Science, 2009

We describe here an alternative approach to direct low-energy electron beam nanolithography process with no conventional deposition of any resist or self-assembled monolayer. The method is based on direct formation of ultrathin dielectric layer on electron irradiated surface, without generation of structural defects. High-quality electron-induced patterns with lateral resolutions of about 10 nm are demonstrated on SiO 2 surface.

Direct-write Electron Beam Lithography: History and State of the Art

MRS Proceedings, 1999

Direct-write electron beam lithography is a patterning technique that has rapidly evolved over the last 40 years. For many years it has been possible to use electrons to pattern lines with widths as narrow as 10 rum. Recent advances in resist materials, electron sources, and system integration have further enhanced the capabilities. High-sensitivity resists provide substantial increases in the throughput without sacrificing resolution. Thermal field-emission sources improve the stability and reduce the minimum attainable spot size. Modem lithography systems integrate the electron beam column with advanced control electronics, making a system capable of nanometer-scale placement accuracy. In addition to these improvements, the technology is more accessible now than ever before, thanks to the proliferation of lithography systems consisting of modified scanning electron microscopes.

Electron beam lithography: resolution limits and applications

Applied Surface Science, 2000

. We report on the resolution limits of Electron Beam Lithography EBL in the conventional polymethylmethacrylate Ž . PMMA organic resist. We show that resolution can be pushed below 10 nm for isolated features and how dense arrays of periodic structures can be fabricated at a pitch of 30 nm, leading to a density close to 700 Gbitrin 2 . We show that intrinsic resolution of the writing in the resist is as small as 3 to 5 nm at high incident electron energy, and that practical resolution is limited by the development of the resist after exposure and by pattern transfer. We present the results of our optimized process for reproducible fabrication of sub-10 nm lines by lift-off and 30-nm pitch pillar arrays by lift-off and reactive ion Ž . etching RIE . We also present some applications of these nanostructures for the fabrication of very high density molds for Ž . nano-imprint lithography NIL and for the fabrication of Multiple Tunnel Junction devices that can be used for single electron device applications or for the connection of small molecules. q 2000 Published by Elsevier Science B.V.

Aberration-Corrected Electron Beam Lithography at the One Nanometer Length Scale

Nano letters, 2017

Patterning materials efficiently at the smallest length scales is a longstanding challenge in nanotechnology. Electron-beam lithography (EBL) is the primary method for patterning arbitrary features, but EBL has not reliably provided sub-4 nm patterns. The few competing techniques that have achieved this resolution are orders of magnitude slower than EBL. In this work, we employed an aberration-corrected scanning transmission electron microscope for lithography to achieve unprecedented resolution. Here we show aberration-corrected EBL at the one nanometer length scale using poly(methyl methacrylate) (PMMA) and have produced both the smallest isolated feature in any conventional resist (1.7 ± 0.5 nm) and the highest density patterns in PMMA (10.7 nm pitch for negative-tone and 17.5 nm pitch for positive-tone PMMA). We also demonstrate pattern transfer from the resist to semiconductor and metallic materials at the sub-5 nm scale. These results indicate that polymer-based nanofabricatio...

Fabrication of high-density nanostructures by electron beam lithography

Journal of Vacuum Science & Technology B: Microelectronics and Nanometer Structures

We demonstrate a fabrication method to define high-density, uniform nanostructures by electron beam lithography at conventional beam voltages ͑Ͻ40 kV͒. Here we optimize the exposure and development conditions needed to generate such nanostructure arrays using polymethylmethacrylate as positive resist and isopropyl alcohol as a developer. Arrays of 12 nm dots with 25 nm period and 20 nm lines with 40 nm period were fabricated to show the resolution of this optimized process.

Limits to Nanopatterning Based on E-Beam Lithography

2014

Ivan Kostič, Nikolaos Glezos, Anna Konecnikova, Ladislav Matay, Pavol Nemec Pavol Pisecny, Dimitrios Velessiotis 1 Institute of Informatics, Slovak Academy of Sciences, Dúbravská cesta 9, 84507 Bratislava, Slovakia 2 International Laser Centre, Ilkovicova 3, 841 04 Bratislava 4, Slovakia 3 Institute of Microelectronics, National Center of Scientific Research Demokritos, Ag. Paraskevi, Athens 15310, Greece E-mail: ivan.kostic@savba.sk