The continuing trend toward higher circuit density in microelectronic devices has motivated research efforts in varieties of high-resolution lithography techniques, including electron beam (EB), X-ray, and deep UV irradiation. Use of ultra-thin films and new materials have been proposed as approaches to improve resolution in lithography. The Langmuir-Blodgett (LB) technique is very effective method used to prepare well-defined ultra-thin film with controlled thickness and orientation at a molecular level. Therefore, LB films are expected to realize ultra-high resolution photolithography [1-4].
In previous studies, [5-7] we have found that N-octadecylacrylamide forms a uniform LB film with a highly ordered structure, and yielded a fine negative pattern by photopolymerization. Furthermore, we have also succeeded in the preparation of preformed polymer LB film that has a cross-linking group . By the cross-linking reaction with deep UV and electron beam irradiation we obtained a fine negative pattern consisting of two-dimensional network. All of these polymer LB films resulted in negative-tone photopatterns. On the other hand, we also obtained positive type photopatterns using poly(N-tetradecylmethacrylamide)(p(TDMA)) LB films without any development process (self-development) [9, 10]. It was found that the higher sensitivity could be obtained by changing the alkyl side chain to the short-branched type . In addition, the deprotection reaction of t-butoxycarbonyloxy group has also been used in positive patterning of polymer LB films [12-14]. Combining these interesting properties, the improvement of not only the sensitivity but also the imaging quality can be expected. In this work, we prepared the copolymers of photodegradable N-tetradecylmethacrylamide (TDMA) with t-butyl 4-vinylphenyl carbonate (tBVPC) (Figure 1) aiming at the fabrication of a new type of positive resist taking place both main chain scission and polarity change caused by t-butoxycarbonyloxy group deprotection.
Decoding cement's shape promises greener concrete
08.12.2016 | Rice University
Scientists track chemical and structural evolution of catalytic nanoparticles in 3-D
08.12.2016 | DOE/Brookhaven National Laboratory
Physicists of the University of Würzburg have made an astonishing discovery in a specific type of topological insulators. The effect is due to the structure of the materials used. The researchers have now published their work in the journal Science.
Topological insulators are currently the hot topic in physics according to the newspaper Neue Zürcher Zeitung. Only a few weeks ago, their importance was...
In recent years, lasers with ultrashort pulses (USP) down to the femtosecond range have become established on an industrial scale. They could advance some applications with the much-lauded “cold ablation” – if that meant they would then achieve more throughput. A new generation of process engineering that will address this issue in particular will be discussed at the “4th UKP Workshop – Ultrafast Laser Technology” in April 2017.
Even back in the 1990s, scientists were comparing materials processing with nanosecond, picosecond and femtosesecond pulses. The result was surprising:...
Have you ever wondered how you see the world? Vision is about photons of light, which are packets of energy, interacting with the atoms or molecules in what...
A multi-institutional research collaboration has created a novel approach for fabricating three-dimensional micro-optics through the shape-defined formation of porous silicon (PSi), with broad impacts in integrated optoelectronics, imaging, and photovoltaics.
Working with colleagues at Stanford and The Dow Chemical Company, researchers at the University of Illinois at Urbana-Champaign fabricated 3-D birefringent...
In experiments with magnetic atoms conducted at extremely low temperatures, scientists have demonstrated a unique phase of matter: The atoms form a new type of quantum liquid or quantum droplet state. These so called quantum droplets may preserve their form in absence of external confinement because of quantum effects. The joint team of experimental physicists from Innsbruck and theoretical physicists from Hannover report on their findings in the journal Physical Review X.
“Our Quantum droplets are in the gas phase but they still drop like a rock,” explains experimental physicist Francesca Ferlaino when talking about the...
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