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The effects of dry cleaning of a HfO2 gate stack using NF3 only and a NF3/NH3 gas mixture plasma were investigated. The plasma dry cleaning process was carried out after HfO2 deposition using an indirect down-flow capacitively coupled plasma (CCP) system. An analysis of the chemical composition of the HfO2 gate stacks by XPS indicated that fluorine was incorporated into the HfO2 films during the plasma dry cleaning. Significant changes in the HfO2 chemical composition were observed as a result of the NF3 dry cleaning, while they were not observed in this case of NF3/NH3 dry cleaning. TEM results showed that the interfacial layer (IL) between the HfO2 and Si thickness was increased by the plasma dry cleaning. However, in the case of NF3/NH3 dry cleaning using 150 W, the IL thickness was suppressed significantly compared to the sample that had not been dry cleaned. Its electrical properties were also improved, including the low gate leakage currents, and reduced EOT. Finally, the finding show that the IL thickness of the HfO2 gate stack can be controlled by using the novel NF3/NH3 dry cleaning process technique without any the significant changes in chemical composition and metal-oxide-semiconductor (MOS) capacitor characteristics.

ZnO-PEG-ZnO complex film was fabricated by forming ZnO thin film on the Polyethyleneglycol (PEG) thin film. ZnO thin films were formed by an electrostatic method and ZnO-PEG complex films were fabricated by adsorbing PEG on the ZnO thin films surface with hydrogen bond. The electrochemical characteristic of the ZnO-PEG-ZnO film was analyzed by EQCM techniques. The resonance frequency, resistance and current changes were measured simultaneously with scan rate 100 mV/s, sweep range -1.4-1.2 V in 5 mM ZnCl2 aqueous solution. The electrochemical characteristic of the ZnO-PEG-ZnO complex film was compared with that of the ZnO thin film, and the possible electrode applications of ZnO-PEG-ZnO complex films were examined.

Micromesoporous magnesium oxide architectures with cubic morphologies were prepared via the chemical reaction of magnesium hydroxide in a supercritical carbon dioxide (CO2)-ethanol system, and via the sequential thermal combustion of the reaction products. The morphological change to the cube shape from an irregular form was induced by the dehydoxylation-carbonation reaction of magnesium hydroxide with supercritical CO2 at a reaction temperature of 150 degrees C, which leads to the greatly improved carbonation efficiency of magnesium hydroxide to magnesium carbonate. The precursor cubes with 3-5 microm sizes were decarbonized and transformed into the nanocrystalline MgO phase with pore sizes of 1.3-6 nm after calcining at 600 degrees C. The micromesoporous cube with high surface area of 117.5 m2/g was obtained by the thermal decarbonation with phase transition from rhombohedral to cubic phase. As a result, nanograined magnesium oxide cubes with micromesoporous structures and high specific surface areas were formed by the carbonation reaction of the magnesium hydroxide with the supercritical CO2, and the subsequent thermal decomposition of the magnesium carbonate cubes.

Identical patterns and characteristics of sub-100 nm TiO2-based memristive systems on 4 inch silicon substrates were demonstrated using Step and flash imprint lithography (SFIL). SFIL is a nanoimprint lithography technique that offers the advantagess of a high aspect-ratio, reliable nano-patterns, and a transparent stamp that can be used to facilitate overlay techniques. The overlay process from the alignment system in IMPRIO 100 was appropriate for the fabrication of nanoscale crossbar arrays in this study. High-density crossbar arrays that consisted of TiO2 resistive switching material that was sandwiched between Pt electrodes with a width of 80 nm and a half-pitch of 100 nm were in turn replicated through successive imprinting and etching processes. The use of the direct metal etching process enhanced the uniformity of the TiO2/Pt interface. The electrical property of the crossbar arrays showed the bipolar switching behavior that resulted in the application of the nonvolatile resistive memory.

This study reports the pattern definable and low cost fabrication of nanopatterned conducting polymer film on flexible substrates. Noble nanopatterned polymer hard template was fabricated by using nanoimprint lithography (NIL) and used for electropolymerization of conducting polymer. Conducting polymer was electrochemically deposited on the template and transferred over to flexible substrates. Eventually conducting polymer films with various nanopatterns were fabricated on flexible substrates. High pattern definability was achieved by nanoimprinted polymer template, which was molded from lithographically fabricated stamp. Low cost fabrication was accomplished due to low cost NIL, reusable polymer templates, and low material consumption of electrodeposition. The electrodeposited films were transferred using double sided tape. Because the templates are made of flexible polymer, the transfer bonding method applied in this study is adaptable to both wafers and flexible polymer substrates. The fabricated nanopatterned conducting polymer film can be applied to gas sensors, super capacitors, super wetting films, and neuron interfaces due to its characteristic of high surface to volume. For an illustrative application, the gas sensing properties of films were tested. The result showed enhanced sensing characteristic with nanopatterned film, which are attributed to the high surface to volume ratio of nanopatterned films.

This study examined the CO oxidation reactivity of Pt deposited on TiO2. The Pt catalysts were prepared by the evaporation of Pt on Ti foils covered with TiO2, and their surface structures were characterized by scanning electron microscopy (SEM) and X-ray photoelectron spectroscopy (XPS). Separate Pt nanoparticles could be observed with lower amounts of deposited Pt (<2 nm). With increasing Pt thickness, these Pt nanoparticles appeared to agglomerate into more complicated nanostructures. When approximately 5 nm of Pt was deposited, the TiO2 surface was almost completely covered by Pt. Additional deposition of Pt on these complete Pt-layers resulted in the deposition of small nanoparticles (approximately 5 nm) on top of the Pt underlayer. The CO oxidation reactivity at 160 degrees C, normalized with respect to the Pt thickness, initially decreased with increasing amount of Pt. This was attributed mainly to the decrease in the surface-to-volume ratio. However, the reactivity increased when the amount of Pt exceeded 5 nm, which can be rationalized in part by the unique structural properties of Pt-films according to SEM imaging. We also suggest that a stronger influence of the metal-support interactions at lower Pt coverages results in reduced catalytic activity.

In this work, we investigated the effect of surface treatment as release layer and adhesion promoter for UV-Nanoimprint lithography and measured the surface adhesion force by using tensile separation force of Instron equipment. Several Self-Assembled Monolayers (SAMs) of 3-Acryloxypropyl methyl dichlorosilane (APMDS) 3-Aminopropyl-triethoxysilane (APTS), and 3-Glycidoxypropyltrimethoxysilane (GPTS) as adhesion promoters and (1H,1H,2H,2H-perfluorooctyl)trichlorosilane (FOTS) as release layer were fabricated by vapor deposition method and were compared with oxygen plasma treatment. APMDS could strongly improve the adhesion force between UV-curable acrylate resin and silicon substrate because of strong covalent bonding. Finally, we could successfully fabricate various imprint patterns by using proper surface treatment of SAMs.

Patterning flexible substrates in nano scale is an important and challenging issue in the fabrication of next-generation devices based on a non-silicon substrate. Step and Flash imprint lithography (S-FIL) which is a room temperature and low pressure process offers several important advantages, such as the use of a smaller and therefore cheaper stamp or the possibility of the overlay imprinting, as a transparent stamp is utilized. However, it is very difficult to perform S-FIL on a flexible substrate successfully due to the high waviness. The waviness of a flexible substrate is not a constant value in contrast to a rigid substrate. It depends on the imprint pressure applied onto the substrate. In this paper, in section two, the effect of the imprint pressure on the waviness of the surface of the flexible substrate is examined. It is proved that the waviness of the surface of the flexible substrate could not be reduced sufficiently to assure a successful imprint at low imprint pressures. In the third section, a method of patterning polymer substrates using ultra-violet nanoimprint lithography (UV-NIL) is presented. The method consists of two stages, stamping-based planarization and S-FIL. In stamping-based planarization, a planarization layer of transparent polymer is formed onto the flexible substrate. Waviness of the blank stamp (in this study, glass wafer) is transferred to the planarization layer. S-FIL is performed with the nanoimprint tool IMPRIO100 directly onto the planarization layer employing a 1 x 1 in. quartz stamp. Optical microscope and SEM images of the successfully imprinted patterns were also presented.

In the ink-jet patterning process, conductive ink composed of metal nanoparticles and solutions, is an important factor for improving properties of printed patterns and processes. In this study, metal (Cu) nanoparticles in conductive ink were synthesized using a modified electrolysis method that extracted to metal nanoparticles from bulk metal plates. The Cu nanoparticles were prepared with a narrow size distribution. The dispersion stability and oxidation properties in conductive inks were also studied. Cu nanoparticles were homogeneous and had a diameter of 15 approximately 20 nm. By addition of PVP, the dispersion and oxidation stability of the metal nanoparticles, which were not oxidized after 2 month, were improved.

In this study indium tin oxide (ITO) nanofibers were synthesized using an electrospinning method. The morphological properties of the ITO nanofibers were considered and their specific resistances were measured to determine their applicability as filler for a transparent conducting film. ITO/PVP composite nanofibers were successfully obtained by electrospinning using a precursor solution containing indium nitrate, tin chloride, and poly(vinlypyrrolidone). After the heat treatment of ITO/PVP composite nanofibers at 600 degrees C and 1000 degrees C, ITO nanofibers with an average diameter of about 168 nm and 165 nm were synthesized, respectively.

Low temperature (less than 600 degrees C) deposition of carbon nanofilaments (CNFs) could be achieved on the silicon oxide substrate by thermal chemical vapor deposition system. We used Fe(CO)5 as the catalyst precursor for CNFs formation. For the enhancement of CNFs formation density, the source gas flow was intentionally manipulated as the cyclic on/off modulation of C2H2/H2 flow during the initial deposition stage. The CNFs formation density on silicon oxide substrate could be much enhanced by the cyclic modulation process having the higher growing/etching time ratio (180/30 s). Furthermore, the lattice structures of CNFs developed into carbon nanotubes at the higher growing/etching time ratio (180/30 s) case. The solely hydrogen gas feeding (C2H2 flow off) time during the initial deposition stage seems to play an important role for the variation in the CNFs formation characteristics by the cyclic modulation process.

Two-dimensional (2-D) and three-dimensional (3-D) diamond-like carbon (DLC) stamps for ultraviolet nanoimprint lithography were fabricated with two methods: namely, a DLC coating process, followed by focused ion beam lithography; and two-photon polymerization patterning, followed by nanoscale-thick DLC coating. We used focused ion beam lithography to fabricate 70 nm deep lines with a width of 100 nm, as well as 70 nm deep lines with a width of 150 nm, on 100 nm thick DLC layers coated on quartz substrates. We also used two-photon polymerization patterning and a DLC coating process to successfully fabricate 200 nm wide lines, as well as 3-D rings with a diameter of 1.35 microm and a height of 1.97 microm, and a 3-D cone with a bottom diameter of 2.88 microm and a height of 1.97 microm. The wafers were successfully printed on an UV-NIL using the DLC stamps without an anti-adhesive layer. The correlation between the dimensions of the stamp's features and the corresponding imprinted features was excellent.