The nanotechnology revolution of the past decade owes much to the science of lithography, an umbrella term which encompasses everything from conventional photolithography to “unconventional” soft lithography and the self‐assembly of block polymers. In this review, some of the recent advances in lithography are summarized with special reference to the microelectronics industry. The next generation photolithography, two‐photon lithography, step‐and‐flash imprint lithography and nanofabrication using block copolymers are covered, in an attempt to describe more recent work in this vibrant and active field of research. Copyright © 2006 John Wiley & Sons, Ltd.

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Extreme ultra violet (EUV) lithography is one of the most promising next generation lithographic techniques for the production of sub-50 nm feature sizes with applications in the semiconductor industry. Coupling this technique with molecular glass resists is an effective strategy for high resolution lithographic patterning. In this study, a series of tert-butyloxycarbonyl (t-Boc) protected C-4-hydroxyphenyl-calix[4]resorcinarenes derivatives were synthesized and evaluated as positive tone molecular glass resists for EUV lithography. The amorphous nature of these molecules was confirmed using thermal analysis, FTIR and powder X-ray diffraction. Feature sizes as small as 30 nm with low line edge roughness (4.5 nm, 3s) were obtained after patterning and development.

This paper describes a series of photoresists constructed from glass-forming, low-molecular-weight organic compounds, also known as molecular glasses. Compared with traditional polymeric resists, molecular glass resists are composed of smaller and more-uniform molecular building blocks. In this work, both positive-tone and negative-tone molecular glass photoresists with a range of core structures were designed and synthesized for study in advanced lithography. These molecular glass resists have asymmetric, rigid cores, which is important for producing glassy materials with glass transition temperatures substantially above room temperature. For positive-tone molecular glass photoresists, amorphous films could be obtained by partial protection of the core structure. Images were produced using photoacid-generator-catalyzed deprotection chemistry. Amorphous negative-tone resists were obtained by mixing molecular glass core structures with another minor resist component such as a photo cross-linker. It was shown by SEC that the molecular weight of the exposed and cross-linked negative-tone resist was less than 2000 g/mol, thus indicating that the solubility change is largely due to a molecular-weight increase. Both types of materials exhibited high sensitivity and resolution. Several resist characteristics were studied to assess their potential as high-resolution resists. These molecular glasses showed high fluorocarbon etch resistance that is comparable to that of poly(hydroxystyrene). Lower line edge roughness was obtained for the negative-tone molecular glass compared to a negative-tone polymeric e-beam resist. The resulting materials exhibited high sensitivity and resolution close to the tool limit under 248 nm exposures when using a chemical amplification process. A well-resolved pattern as small as 50 nm was obtained for the negative-tone molecular glass by e-beam exposure, indicating the excellent potential of using low molecular molar mass molecular glasses to form high-resolution structures.

Cubic liquid-crystalline nanoparticles prepared from aqueous dispersions of cubic lipid-water phases are kinetically stable in the presence of certain dispersing agents. The properties of cubic nanoparticles from monoolein-water and other lipid-water systems have been examined with a variety of experimental techniques. The cubic nanoparticles can be stabilized by polymerization of the reactive lipids in cubic lipid assemblies. Several low-energy-input methods have been developed to facilitate the production and application of cubic nanoparticles. The ability to incorporate and deliver lipophilic, amphiphilic, and water-soluble molecules in a controlled manner and the good biocompatibility of cubic nanoparticles make them excellent candidates for drug-delivery applications.