春山 雄一

In the UV nanoimprinting process an antisticking layer such as fluorinated self-assembled monolayer (F-SAM) is grafted on the mold surface to diminish the demolding impact. These layers are supposed to deteriorate as the imprint steps mount up, resulting in defects in the cured resist layer. In this work, continuous multiple shots of UV nanoimprint were conducted in the air and in pentafluoropropane (PFP) gas environment and demolding forces in every imprint step were determined. The experiments revealed that the demolding forces for the imprint in PFP atmosphere drastically reduced compared with those in the air. Water contact angles of the mold surface were also determined in every 225 imprint steps to observe the degree of degradation of the antisticking layer. It was found that the antisticking layer was less damaged or contaminated in the PFP environment than it was in the air after a certain number of imprint steps.

The low-temperature activation and the suppression of anomalous diffused B by using SR soft X-ray were investigated for ultra shallow junction. The transient enhanced diffusion due to the interstitial B clusters can be suppressed by using soft X-ray.

It had been reported that tri-phenysulfonium cyclo(1,3-perfluoropropanedisulfone) imidate (TPS-IMIDATE) as a photo acid generator has approximately four times faster sensitive rather than tri-phenysulfonium perfluorobutanesulfonate (TPS-PFBS) under the EUV exposure. In this paper, we discussed the differences of the sensitivity and the chemical reaction between TPS-IMIDATE and TPS-PFBS, on the basis of the EUV-induced analysis of the SR absorption spectroscopy. From the analysis of the SR absorption spectroscopy, F and C atoms in the anion of TPS-IMIDATE decomposed rather than that of TPS-PFBS. The sensitivity advantage of TPS-IMIDATE might own to the anion decomposition reaction. The anion decomposition reaction might be originated to the photo-excitation of the photoacid generator. The anion of TPS-IMIDATE decomposed to smaller molecule and the sensitivity becomes higher.

Ultraviolet (UV) nanoimprinting is a useful technique to fabricate nanostructure devices with high throughput, high resolution, and low cost. To eliminate bubble defects, one of the main problems in UV nanoimprinting, UV nanoimprinting in an atmosphere of pentafluoropropane (PFP) gas, which is a condensable gas, is proposed. This process has been reported to reduce the demolding force. To examine the PFP gas effect in a nanometer-scale area, adhesion and frictional forces were measured by scanning probe microscopy in a PFP gas atmosphere. The results show that the adhesion and frictional forces measured by scanning probe microscopy in a PFP gas atmosphere were lower than those measured in air and a N-2 gas atmosphere. Furthermore, the adhesion and frictional forces were found to depend on the PFP gas pressure. (C) 2012 American Vacuum Society. [DOI: 10.1116/1.3665989]

Nanoscale imprinted pillars were fabricated with three resin systems and characterized by measuring the spring constant using a scanning probe microscopy cantilever manipulated with a three-axis actuator. The functional dependence of the spring constant on the height and diameter of the pillar was then used to determine the Young's modulus. Nanoindentation was used to determine the Young's modulus of the base film. Before high temperature annealing, the Young's modulus of the imprinted pillar was nearly the same as that of film. After the annealing, the Young's modulus of the imprinted pillar was lower than that of the film. (C) 2011 American Vacuum Society. [DOI: 10.1116/1.3657520]

The antisticking capabilities and durability of thin poly(dimethylsiloxane) (PDMS) were compared to a fluorinated antisticking layer (F-ASL) to assess its suitability for use in UV nanoimprint lithography (UV-NIL). Typically, UV-NIL is used to fabricate high-throughput, low-cost, high-resolution nanostructure devices. The nanoimprint mold is typically coated with an antisticking layer to ensure easy separation of the mold from the UV nanoimprint resins. This layer must be highly durable to meet the demands of a manufacturing environment, and F-ASL is the standard type used. In PS-b-PDMS block copolymer lithography, the template is coated with a thin layer of PDMS. In this study, we focused on using PDMS as the antisticking layer for nanoimprinting and examined its antisticking capabilities and durability by step and repeat (S&R) UV nanoimprinting. Experimental results showed that the thin PDMS layer functions comparably to the F-ASL as an antisticking layer. (C) 2011 American Vacuum Society. [DOI: 10.1116/1.3653226]

Ultraviolet (UV) nanoimprint lithography is used to fabricate nanostructured devices with high-throughput, low cost, and high resolution. The nanoimprint mold is coated with an antisticking layer to enable easy separation of the mold from the UV nanoimprint resins. An important issue is finding a way to prevent the deterioration of the antisticking layer which results from repeated UV nanoimprinting. To do this, a UV nanoimprint resin with release properties is required. The authors evaluated the effect of a fluorine additive on a cationic UV-curable resin by x-ray photoelectron spectroscopy (XPS), scanning probe microscopy, and contact angle measurement. The authors confirmed from the XPS results that fluorine was present on the surface of the cured UV-curable resin with the fluorine additive. Furthermore, the adhesion and frictional forces of the UV-curable resin with the fluorine additive were lower than those of the UV-curable resin without the additive. (C) 2011 American Vacuum Society. [DOI: 10.1116/1.3653513]

The authors have previously used two methods for nanoimprinting hydrogen silsesquioxane (HSQ) patterns. In the casting method, the HSQ pattern was replicated at a low imprinting pressure of less than 1 MPa, however, the imprinting produced an uneven residue. On the contrary, in the spin-coating method, an evenly distributed HSQ film was produced. However, the HSQ pattern required a high imprinting pressure of about 40 MPa. To achieve imprinting at a low pressure with the spin-coating method, we propose a new room temperature nanoimprinting method using spin-coated HSQ and a poly(dimethylsiloxane) mold. The authors used high boiling point solvent, with a boiling point of greater than 200 degrees C, in place of the previously used solvent that had a boiling point of 96 degrees C. This method produced an evenly coated film in the liquid-phase. (C) 2011 American Vacuum Society. [DOI: 10.1116/1.3653227]

The formation of bubble defects during UV-nanoimprinting can be prevented by carrying out the process in a 1,1,1,3,3-pentafluoropropane (PFP) gas environment. The authors therefore evaluated the curing time and the calorific value of UV-curable resins in a PFP gas environment by photo differential scanning calorimetry and their polymerization degree by Fourier transform infrared spectroscopy. The authors found that UV-curable resins polymerized more efficiently in PFP than in air because PFP dissolves in the resins. (C) 2011 American Vacuum Society. [DOI: 10.1116/1.3656022]

Bubble defects in ultraviolet (UV) nanoimprinting can be eliminated by carrying out the procedure in pentafluoropropane (PFP) gas ambient. Furthermore, the viscosity of the UV-nanoimprint resin is about one-fifth lower than that in air. The authors assume from these results that the PFP gas dissolves into the UV-nanoimprint resin, and the dissolved PFP might affect the characteristics of UV-nanoimprint resin. In this experiment, we analyzed the properties of PFP-dissolved UV-nanoimprint resin using a Fourier transform infrared (FT-IR) spectrometer and contact-angle meter. First, we measured the FT-IR spectrum. The results for resins in PFP gas ambient showed a peak due to the stretching vibration of the C-F bond before and after UV irradiation. Next, the sliding angles and speeds of resins were measured by measurement of the sliding angle in air and PFP gas ambient. The sliding speeds in PFP gas ambient were five times those in air and the sliding angles were one-fourth lower than those in air. The increase in sliding speeds and the decrease in sliding angles in PFP gas ambient were due to the PFP gas dissolving into the resin. (C) 2011 American Vacuum Society. [DOI: 10.1116/1.3662856]

The orientation of molecules in photoinduced liquid crystalline polymer film was studied by means of a thermal nanoimprinting technique using a SiO2/Si mold with a line-and-space (L&S) pattern. If nanoimprinting reorients molecules in photoinduced liquid crystalline polymer, unique characteristics may result from carrying out nanoimprinting and linearly polarized UV (LPUV) irradiation at the same time. We found that the imprinted photoinduced polymer was oriented parallel to the line pattern on the mold. Furthermore, we found that photoinduced liquid crystalline polymer films that were pre-aligned by LPUV irradiation and a heat treatment could be reoriented by thermal nanoimprinting. (C) 2011 Elsevier B.V. All rights reserved.

Surface modification of diamond-like carbon (DLC) film was performed using a hyperthermal atomic fluorine beam on the purpose of production of hydrophobic surface by maintaining the high hardness of DLC film. By the irradiation of atomic fluorine beam of a 1.0 x 10(20) atoms/cm(2), the contact angle of a water drop against the DLC surface increased from 73 degrees to 111 degrees. The formation of CF3, CF2 and CF bonding on the modified DLC surface was confirmed from the measurements of X-ray photoelectron spectra and near-edge X-ray absorption fine structure spectra. Irradiation of hyperthermal atomic fluorine beam was concluded to produce insulator fluorine-terminated DLC film, which has high F content on the surface. by the taking of the use of neutral atomic beam as a fluorine source. (C) 2011 Published by Elsevier B.V.

The dynamics of magnetostatically coupled vortices in a pair of ferromagnetic micron-sized disks has been observed in real space by pump-probe time-resolved photoemission electron microscopy. It is found that the dynamics of paired vortices is affected by a magnetic dipolar interaction. The displacement of a vortex core from its equilibrium position in the paired vortices during the supply of a magnetic field pulse is smaller than that in the isolated vortex, which is in qualitative agreement with micromagnetic simulation results. Unexpectedly, two eigenfrequencies of the paired vortices are different from each other. When the separation distance between the paired disks is shorter, the difference between the two eigenfrequencies is larger. (C) 2011 The Japan Society of Applied Physics

The electronic structure of fluorinated diamond-like carbon (F-DLC) thin films was investigated by the photoelectron spectroscopy. The photon energy dependence of the photoelectron spectra in the valence band region was measured from 70 to 420 eV and the orbital components of the photoelectron spectra in the valence band region were clarified. In addition, the chemical composition and components of the F-DLC thin films as a function of the annealing temperature were determined by the measurements of photoelectron spectra in the F 1s and C 1s core-levels. Based on the results of the photoelectron spectroscopy measurements as a function of the annealing temperature, the electronic structure of the F-DLC thin films is discussed. (C) 2011 Elsevier B.V. All rights reserved.

The authors have previously used two methods for nanoimprinting hydrogen silsesquioxane (HSQ) patterns. In the casting method, the HSQ pattern was replicated at a low imprinting pressure of less than 1 MPa, however, the imprinting produced an uneven residue. On the contrary, in the spin-coating method, an evenly distributed HSQ film was produced. However, the HSQ pattern required a high imprinting pressure of about 40 MPa. To achieve imprinting at a low pressure with the spin-coating method, we propose a new room temperature nanoimprinting method using spin-coated HSQ and a poly(dimethylsiloxane) mold. The authors used high boiling point solvent, with a boiling point of greater than 200 °C, in place of the previously used solvent that had a boiling point of 96 °C. This method produced an evenly coated film in the liquid-phase. © 2011 American Vacuum Society.

Nanoscale imprinted pillars were fabricated with three resin systems and characterized by measuring the spring constant using a scanning probe microscopy cantilever manipulated with a three-axis actuator. The functional dependence of the spring constant on the height and diameter of the pillar was then used to determine the Young's modulus. Nanoindentation was used to determine the Young's modulus of the base film. Before high temperature annealing, the Young's modulus of the imprinted pillar was nearly the same as that of film. After the annealing, the Young's modulus of the imprinted pillar was lower than that of the film. © 2011 American Vacuum Society.

The antisticking capabilities and durability of thin poly(dimethylsiloxane) (PDMS) were compared to a fluorinated antisticking layer (F-ASL) to assess its suitability for use in UV nanoimprint lithography (UV-NIL). Typically, UV-NIL is used to fabricate high-throughput, low-cost, high-resolution nanostructure devices. The nanoimprint mold is typically coated with an antisticking layer to ensure easy separation of the mold from the UV nanoimprint resins. This layer must be highly durable to meet the demands of a manufacturing environment, and F-ASL is the standard type used. In PS-b-PDMS block copolymer lithography, the template is coated with a thin layer of PDMS. In this study, we focused on using PDMS as the antisticking layer for nanoimprinting and examined its antisticking capabilities and durability by step and repeat (S&amp R) UV nanoimprinting. Experimental results showed that the thin PDMS layer functions comparably to the F-ASL as an antisticking layer. © 2011 American Vacuum Society.

Nanoimprint lithography (NIL) is a very useful technique for replicating planar nanostructures at low cost with high throughput, but an expansion from planar to nonplanar will probably be required to enhance the functional capabilities of nanodevices. On the other hand, focused-ion-beam chemical vapor deposition (FIB-CVD) is a promising technology for fabricating nonplanar nanostructures. In this study, the authors demonstrated a new nonplanar replication method using a combination of FIB-CVD and NIL to achieve nonplanar replication with submicrometer feature sizes. Furthermore, they replicated nonplanar nanostructures by using step and repeat NIL. © 2011 American Vacuum Society.

Molecular orientation in a photo-crosslinkable liquid crystalline polymer (PLCP) film was explored by a thermal nanoinprinting technique using a SiO2/Si mold with a line-and-space (L&S) pattern. A molecular oriented structure was confirmed by polarization optical microscopy and diffraction efficiency measurements, at which the reoriented direction was parallel to the mold lines. We demonstrated thermal nanoimprinting on prealigned PLCP films by linearly polarized UV (LPUV) and evaluated the optical characteristics of imprinted PLCP films. As a result, the prealigned PLCP films were reoriented by thermal nanoimprinting.

UV nanoimprint lithography is used to fabricate nanostructure devices with high throughput, low cost, and high resolution. UV-curable resins are one important factor in UV nanoimprinting and they are mainly categorized into two reaction types: radical and cationic curing systems. A drawback of the radical curing system is curing inhibition by oxygen. To evaluate the oxygen inhibition for UV-curable resins, the authors measured the force curve transition by scanning probe microscopy with an UV irradiation system. With this system, the authors are able to measure in situ the UV dose dependence of the force curve transition on the same UV-curable resin. Measurements showed that the curing speed of radical UV-curable resin in vacuum became 800 times higher than that in air due to oxygen inhibition. Furthermore, for a cationic UV-curable resin, although the curing reaction of a cationic UV-curable resin is not affected by oxygen, the authors observed that the curing speed in vacuum at about 15 Pa became 4.5 times higher compared to that in air. The curing reaction of a cationic UV-curable resin may be inhibited by alkali. (C) 2010 American Vacuum Society. [DOI:10.1116/1.3517511]

Nanoimprint lithography (NIL) is a simple process for fabricating nanostructure devices. There are many factors in nanoimprinting such as nanoimprint pressure, an antisticking layer, temperature, and the viscosity of resin. Although these factors affect the imprinted pattern, the nanoimprint mechanism has not been resolved. The flow behavior during nanoimprinting is important for investigating the nanoimprint mechanism. We propose a cross-sectional observation method for filling a nm-scale pattern with nanoimprint resins after nanoimprinting using scanning electron microscopy (SEM). A polyvinyl alcohol (PVA), which is soluble in water, was used in this observation. We demonstrated the cross-sectional observation of UV-, thermal-, and room temperature-nanoimprint resins using the proposed method. (C) 2009 Elsevier B.V. All rights reserved.

The chemical composition and components of a synchrotron radiation (SR) irradiated polytetrafluoroethylene (PTFE) surface were investigated as a function of the annealing temperature by the X-ray photoelectron spectroscopy (XPS). When the annealing temperature of SR irradiated PTFE was less than 150 °C, almost no change was observed in XPS spectra. With increasing the annealing temperature at more than 200 °C, the relative intensity of the F 1s peak to the C 1s peak increased gradually. In addition, the intensity of the CF₂ component also increased. These results indicate that the chemical composition and components of the SR irradiated PTFE surfaces are restored by annealing. Based on the XPS spectra, the annealing effect on the chemical composition and components is discussed.

A new room-temperature imprinting method was developed using liquid-phase hydrogen silsesquioxane (HSQ) with a hard poly(dimethylsiloxane) (h-PDMS) mold. The simultaneous imprinting of arbitrary patterns including both submicron and greater than 100 mu m patterns on a 4-in. wafer were replicated at room-temperature and a low pressure with high throughput, because the solvent in HSQ gradually evaporated through the pores of the h-PDMS mold. A bilayer structure was successfully fabricated using as HSQ pattern as an etching mask without removing the residual layer. (C) 2010 The Japan Society of Applied Physics

The direct patterning of low-dielectric constant (low-k) materials via nanoimprint lithography (NIL) has the potential to simplify fabrication processes and significantly reduce the manufacturing costs of semiconductor devices. It is known that a low k is realized by introducing a large number of nanoscale pores into a material. We demonstrated nanoimprinting on a sol-gel low-k material (k similar to 2.0) formed using methyl silicate as a siloxane oligomer source and surfactants as a pore template. As a result, 200-nm-linewidth mold patterns were successfully transferred onto the sol-gel low-k material by thermal nanoimprinting at 200 degrees C. However, pattern shrinkage was observed. The imprinted pattern linewidth was 180 nm. We assumed from the Fourier transform infrared spectroscopy (FT-IR) spectra of the sol-gel film before and after baking that the pattern shrinkage was induced by the condensation reaction. (C) 2010 The Japan Society of Applied Physics

The spin-coated ITO film can be delineated by room-temperature nanoimprint lithography (RT-NIL), but the patterns disappeared after 200 degrees C annealing process. To overcome the above problem, we examined 254 nm UV irradiation effect onto a spin-coated ITO film. However, this result suggests that UV irradiated pattern shrink in size. In this paper, we confirmed UV irradiation effect on pattern shrinkage of sol-gel ITO replicated by RT-NIL.

The mechanical characteristics of iron-containing nanosprings (Fe-containing nanosprings) fabricated by focused-ion-beam chemical vapor deposition (FIB-CVD) using a ferrocene (C10H10Fe) source gas were investigated. The shear and Young's moduli were 34 and 92 GPa, respectively. We also evaluated the annealing effect of Fe-containing nanosprings and observed a droplet containing Fe and Ga on the nanospring after annealing at 600 degrees C. The spring constant rapidly decreased after annealing at 600 degrees C. By scanning electron microscopy energy-dispersive X-ray spectroscopy (SEM-EDX) and transmission electron microscopy energy-dispersive X-ray spectroscopy (TEM-EDX) line analysis, it was confirmed that the decrease in the spring constant was due to Ga removal. (C) 2010 The Japan Society of Applied Physics

The authors report the first room-temperature nanoimprint lithography (RT-NIL) process using sol-gel indium tin oxide (ITO) as a replicated material. The spin-coated ITO film has to be annealed over 600 degrees C to obtain a low resistivity. The spin-coated ITO film can be delineated by RT-NIL, but the patterns disappear after annealing at 200 degrees C. To overcome the above problem, they examined UV irradiation effects on a spin-coated ITO film. As a result, they found that the ITO patterns imprinted by RT-NIL stayed the same after being annealed at 600 degrees C for 1 h due to 254 nm UV irradiation before annealing.

We performed a nanostructure analysis of diamond-like carbon (DLC) nanowires used to compose nanosprings fabricated by focused-ion-beam chemical vapor deposition (FIB-CVD). The DLC nanowires of the as-grown nanosprings had elastic double structures, in which a 50-nm-diameter core containing 3-at. % gallium (Ga) in addition to carbon (C) was enclosed in an outer 25-nm-wide DLC shell. The Young's modulus of the core was 322 GPa, approximately 12 times that (26 GPa) of the DLC shell. Energy dispersion X-ray spectroscopy (EDX) revealed that the C densities of the core and the shell were similar, indicating that the density of the core was higher than that of the shell owing to the incorporation of Ga into the core. However, the core density was approximately halved by 800 degrees C annealing. This is attributed to the vaporization of Ga and the movement of C from the core to the shell. (C) 2009 The Japan Society of Applied Physics

Photoelectron spectra of the valence band region in diamond, diamond-like carbon (DLC), glassy carbon, and graphite were measured in order to investigate the influence of the carbon atom coordination on photoelectron spectra. Differences in the photoelectron spectra were observed, depending on the coordination of the carbon atoms. The photoelectron spectra for DLC and glassy carbon were compared to those simulated using the photoelectron spectra for diamond and graphite. From this comparison, it was found that the photoelectron spectra in DLC could not be simply reproduced using those for diamond and graphite. In addition, the photoelectron spectra of the valence band region in DLC were compared to the density of states previously calculated using the molecular dynamics method. (C) 2009 The Japan Society of Applied Physics

Nanoimprint lithography (NIL) is very useful for mass-producing nanostructure devices at a low cost and a high throughput. To avoid the adhesion of replication materials, NIL molds are usually coated with an antisticking fluorinated self-assembled monolayer. In this study, we used a fluorinated plasma chemical vapor deposition film as the antisticking layer. First, we formed a CHF3 plasma chemical vapor deposition (CVD) film on SiO2/Si and quartz molds and carried out thermal and UV nanoimprint using these molds. However, the film was removed from these molds. We found that the proposed method can solve this problem. We irradiated plasma using a gas mixture of CHF3 and O-2 as the source gas onto SiO2/Si and quartz molds. As imprinting results, the patterns were successfully imprinted onto the resins without the removal of the plasma CVD film. In addition, we were able to carry out 100 times of repeated nanoimprinting using the plasma-CVD-film-coated SiO2/Si mold. (C) 2009 The Japan Society of Applied Physics

The electronic structure in hydrogenated amorphous carbon (a-C:H) thin films as a function of annealing temperature was investigated by photoemission spectroscopy. The photoemission results of the valence band and the C 1s core level suggested that the graphitization of a-C:H films proceeds by annealing at more than 400 degrees C. From the photoemission spectra of the C 1s core level, the coordination of C atoms in a-C:H films was evaluated as a function of annealing temperature. On the basis of the evaluations, the electronic structure of a-C:H films as a function of annealing temperature is discussed. (C) 2009 The Japan Society of Applied Physics

A fluorinated self-assembled monolayer (F-SAM) is mainly used as the antisticking layer. To prevent the F-SAM coated on the nanoimprint lithography (NIL) mold from deteriorating, we propose a new form of nanoimprinting using a release-agent-coated resin. The results from measuring the surface free energy and observations by scanning probe microscopy (SPM) confirmed that the surface free energy, frictional force, and adhesion force of the release-agent spray-coated polymethylmethacrylate (PMMA) were lower than those of PMMA. To prove the release-agent spray-coated PMMA had a releasing effect, we tried to undertake thermal nanoimprinting on it using a mold without F-SAM. The pattern was clearly imprinted on the resin without any signs of adhesion. (C) 2009 Elsevier B.V. All rights reserved.

In nanoimprint lithography (NIL), a mold is coated with an antisticking layer for preventing resin from adhering to it. A fluorinated self-assembled monolayer (F-SAM) is mainly used as the antisticking layer. The temperature of the mold in thermal NIL increases around the glass transition temperature of the resin. It is therefore important to assess the durability of the antisticking layer against heat. We evaluated the releasing effect of F-SAMs with and without annealing by using measurements obtained from the surface free energy and scanning probe microscopy (SPM). Furthermore, we examined the surface chemical composition and the surface morphology of F-SAMs with and without annealing using X-ray photoelectron spectroscopy (XPS), Fourier transform infrared spectroscopy (FT-IR), and atomic force microscopy (AFM). From these results, we confirmed that the releasing effect of F-SAM deteriorated due to thermal decomposition when annealing over 500 degrees C. However, we found that F-SAMs annealed at 500 degrees C had a sufficiently large releasing effect in nanoimprinting. (C) 2008 Elsevier B.V. All rights reserved.

We have investigated the Au-SrTiO3(100) interface as a function of the Au evaporation using the photoemission spectroscopy. In the valence band of SrTiO3, the broad state originating from O 2p electrons and a state from Ti 3d electrons were observed between 3-9 eV and at 1 eV below the Fermi level (EF), respectively. With increasing the Au evaporation, the decrease in intensity of the state at 1 eV was observed. In the Ti 3p core-level, the decrease of the Ti3+ states was observed after Au evaporation. These results indicate that the electrons transfer from the Ti 3+ states of the SrTiO3(100) surface to the evaporated Au. In addition, with increasing the Au evaporation, the larger shift of the peak in the Au 4f core-level to lower binding energy side was clearly observed as compared to that of the Sr 4p, O 2s, Ti 3p, and Sr 3d core-levels. Based on the results of the photoemission spectroscopy of the valence band and core-levels, we will discuss the electronic structures of the Au-SrTiO3(100) interface. © 2009 The Institute of Electrical Engineers of Japan.

We report room-temperature nanoimprint (RT-NIL) process using sol-gel indium tin oxide (ITO) as a replicated material. The spin-coated ITO film has to be annealed at over 600 degrees C to obtain a low resistivity. The spin-coated ITO film can be delineated by RT-NIL, but the patterns disappeared after 200 degrees C annealing process. To overcome the above problem, we examined the O(2) plasma irradiation effect onto a spin-coated ITO film. As a result, we found that the ITO patterns imprinted by RT-NIL were kept at anneahng of 600 degrees C for 1 hour by O(2) plasma irradiation before annealing.

We have newly developed an imprinting technique using liquid-phase hydrogen silsesquioxane (HSQ) with Poly(dimethyl siloxane) (PDMS) mold. The patterns with various linewidth were demonstrated by imprinting using liquid-phase HSQ. And then, after imprinting, the residual HSQ layer that remained in the compressed area was less than 10 nm thick because the solvent in HSQ smoothly evaporated through the pores of PDMS mold.

Room temperature nanoimprint lithography (RT-NIL) is a simpler process than thermal and UV NIL because it can be carried out without a resist thermal cycle and UV exposure. A fluorinated self-assembled monolayer (F-SAM) is mainly used as an antisticking layer. However, the F-SAM deteriorates due to repeated nanoimprinting. To prevent the F-SAM coating on the NIL mold from deteriorating, we propose a new imprinting technique using release-agent spray-coated hydrogen silsesquioxane (RASC-HSQ). We carried out RT-NIL onto it using a mold without F-SAM. The pattern was successfully imprinted on the resin without any signs of adhesion. (C) 2009 The Japan Society of Applied Physics

In nanoimprint lithography (NIL) molds are in direct contact with replication materials. Furthermore, the glass transition temperature is. around 100-200 degrees C in thermal NIL. We examined the temperature dependence of a release effect for the antisticking layer of a self-assembled monolayer with a fluoropolymer by scanning probe microscopy (SPM). We measured the contact angle and frictional force of the antisticking layer with and without annealing. The contact angle decreases and the frictional force increases at annealing temperatures greater than 500 degrees C. We analyzed the chemical composition of the antisticking layer with and without annealing by X-ray photoelectron spectroscopy (XPS). From the obtained measurement results, the CF(3) and CF(2) peaks of the antisticking layer disappeared after annealing at temperatures greater than 500 degrees C. These results show that the antisticking layer annealed at temperatures less than 500 degrees C has a sufficient release effect.

Materials deposited by focused-ion-beam chemical vapor deposition (FIB-CVD) have numerous interesting material characteristics. They contain gallium (Ga) because Ga is implanted by Ga(+) FIB irradiation. Atomic ratios of the diamond-like carbon (DLC) deposited using phenanthrene (C(14)H(10)) as a gas source for FIB-CVD has the ratio of C : Ga = 95 : 5. And, It is also noted that the incorporated Ga in DLC is again segregated from DLC by annealing treatment. In this study, we found that Ga became agglomerated and was separated out from DLC by annealing treatment. Furthermore, Ga was passed out preferentially through the structural defect onto the DLC surface. Furthermore, the eduction position control of Ga sphere could be achieved using the via hole fabricated on the nanostructure by FIB-etching. This technique is utilizable for the formation of of junctions, such as a nano-bumps, to combine nanoelectromechanical devices.

UV-nanoimprint lithography (NIL) has the potentiality to enable fabrication of nanostructures with high-throughput and low cost. The template is a key element in UV-NIL. Template patterns are directly transferred into the replicated materials. A repair technique is indispensable for UV-NIL template fabrication. However, only a few reports have appeared on the repair of UV-NIL templates. In this study, program protrusion and hollow defects on UV-NIL templates have been repaired by focused-ion-beam (FIB) etching and SiO(x) chemical vapor deposition (CVD) using tetraethoxysilane as a source gas. The imprinted line patterns were successfully replicated by UV-NIL using the repaired templates. Moreover, it has been confirmed that FIB etching and CVD can be Applied to repair 30-nm defects on quartz templates.

The coordination of C atoms in diamond-like carbon (DLC) thin films formed by Ar gas cluster ion beam (GCIB) assisted deposition using fullerene as a carbon source was investigated using X-ray photoelectron spectroscopy (XPS) and near-edge X-ray absorption fine structure (NEXAFS) spectroscopy. From the curve fitting analysis of XPS spectra of the C 1s core level, the absolute sp(2) and sp(3) contents in the DLC films formed by Ar GCIB-assisted deposition were evaluated for the first time. The absolute sp(3) content of DLC films formed by the GCIB-assisted deposition at an acceleration voltage of 5 kV was the highest compared with that formed at 7 and 9 kV. In addition, the absolute sp(2) contents evaluated from XPS spectra were compared to the relative sp(2) contents evaluated from NEXAFS spectra. [DOI: 10.1143/JJAP.47.3380]

Structure of the corrosion product films, which formed on hot-dip Zn-0.2%Al, Zn-5%Al and Zn-55%Al coatings in the early stages of corrosion reaction under the presence of NaCl particles, have been investigated by means of photoemission spectroscopy using synchrotron radiation and Al-Kα radiation. As a result, it is found that the surface compound of initial oxide film on Zn-Al coating changes from zinc oxide to aluminum oxide with increasing Al content, and that the structure depends on Al content. Additionally, the dominant compound of 1 nm or less in depth from the surface of corrosion products is seen to be different from that of 4 nm or less in depth. The corrosion resistance of Zn-Al coating is considered to be attributed to the depth profile of corrosion products on coating.

The control of wettability on a diamond-like carbon (DLC) thin film was carried out by exposing the film to synchrotron radiation (SR) ranging 50-1000 e V under perfluorohexane (C(6)F(14)) gas atmosphere. The contact angle of the DLC surface with a water droplet was found to increase from 73 degrees to 114 degrees by the SR irradiation under C(6)F(14) gas atmosphere. The chemical components variations of the DLC surface were studied using X-ray photoelectron spectroscopy and the modified DLC film with F was studied using near-edge X-ray absorption fine structure spectroscopy. By mounting the new sample holder for the parallel SR irradiation, we succeeded in preventing secondary reaction of deposited material and controlling the contact angle of the fluorocarbon modified DLC surface. (C) 2007 Elsevier B.V. All rights reserved.

Diamond-like carbon (DLC) deposited by focused-ion-beam chemical vapor deposition (FIB-CVD) contains gallium (Ga) when a Ga ion beam is used. Therefore, DLC deposited by FIB-CVD (FIB-DLC) has specific material characteristics that differ from those of typical DLC. In this study, FIB-DLC's annealing-temperature dependence of field emission properties, work functions, and surface conditions were measured to understand its material characteristics. The results show that Ga incorporation is required in order to obtain a sufficient electric conductivity for the field emission. Furthermore, we found that the work function is increased by the graphitization of the FIB-DLC surface caused by the annealing treatment.