Electron-beam lithography

About: Electron-beam lithography is a research topic. Over the lifetime, 8982 publications have been published within this topic receiving 143325 citations. The topic is also known as: e-beam lithography.

Soldering to a single atomic layer

Abstract: The standard technique to make electrical contact to nanostructures is electron beam lithography. This method has several drawbacks including complexity, cost, and sample contamination. We present a simple technique to cleanly solder submicron sized, Ohmic contacts to nanostructures. To demonstrate, we contact graphene, a single atomic layer of carbon, and investigate low- and high-bias electronic transport. We set lower bounds on the current carrying capacity of graphene. A simple model allows us to obtain device characteristics such as mobility, minimum conductance, and contact resistance.

Micromachining using deep ion beam lithography

Abstract: In recent years the process combining deep X-ray lithography with electroforming and micromoulding (i.e. LIGA), has become an important technique for the production of high aspect-ratio microstructures for the fabrication of micro-electromechanical systems (MEMS). The aim of this paper is to investigate the potential of high energy ion microbeams for carrying out similar micromachining, and in particular for overcoming the geometrical restrictions which are inherent in deep x-ray lithography. Using a scanned 2.0 MeV proton beam of approximately 1 micron diameter, we produced latent microstructures in high molecular weight PMMA resist. These resist microstructures were subsequently developed using a multi-component developer which is highly specific in the removal of exposed resist, while leaving unexposed or marginally exposed material unaffected. A suitable range of exposures has been established, and factors affecting the geometrical fidelity of the produced microstructure have been investigated. The relative advantages and limitations of this technique vis a vis deep X-ray lithography are discussed.

Lithographic Fabrication of Model Systems in Heterogeneous Catalysis and Surface Science Studies

Abstract: Lithographic technologies are applied to fabricate model systems for surface science and heterogeneous catalysis studies. An ordered metal nanocluster array fabricated on oxide substrates is also an ideal model system of supported industrial catalysts. Taking advantage of an ordered nanocluster array fabricated by electron beam lithography, the thermal and chemical stability of supported silver catalysts are examined in both oxidizing and reducing conditions. In reducing conditions, the supported silver nanoparticles are stable up to {approx}700 C. In oxidizing conditions, however, the silver nanoparticles are oxidized below 200 C, and conglomerate to micrometer-size amorphous clusters {approx}400 C. The supported nanocluster sample can also be adapted to study reactivity of supported metal catalysts, as confirmed by measurement of ethylene hydrogenation turnover rates on platinum nanoparticle samples. Lithographic technologies can also fabricate model systems for other surface science research. A nanometer scale pattern is created on a poly(methyl methacrylate) (PMMA) surface by electron beam lithography. The sample is adapted to test a recent development in nanotribology, in which surface elastic modulus (hardness) is determined by a modified atomic force microscope. In addition, lithographically fabricated supported nanostructures are used to image the AFM tip (thereby determining the radius of curvature of the tip), whichmore » is a critical parameter for the quantification of surface mechanical properties such as elastic modulus. Finally, taking advantage of the uniform height profile of lithographically fabricated nanostructures, ion sputtering yield can be determined by the reduction of nanostructure height as a function of ion exposure.« less

Emission lifetime of polarizable charge stored in nano-crystalline Si based single-electron memory

Abstract: The lifetime of the emission of a single electron stored in a nanocrystalline Si (nc-Si) dot has been studied in order to understand the physical processes for memory applications. A small active area field effect transistor channel (50×25 nm) is defined by electron-beam lithography on a thin (20 nm) silicon-on-insulator channel and allows for the electrical isolation of a single nc-Si dot. Remote plasma enhanced chemical vapor deposition is used to form 8±1 nm diameter nc-Si dots in the gas phase from a pulsed SiH4 source. Electrons stored in a dot results in an observed discrete threshold shift of 90 mV. Analysis of lifetime as a function of applied potential and temperature show the dot to be an acceptor site with nearly Poisson time distributions. An observed 1/T2 dependence of lifetime is consistent with a direct tunneling process, and interface states are not the dominant mechanism for electron storage in this device structure. Median emission lifetimes as a function of applied gate bias are readily...