Single Nano Research Articles

Theoretical study of fabrication of line-and-space patterns with 7 nm quarter-pitch (7 nm space width and 21 nm line width) using electron beam lithography with chemically amplified resist processes: I. Relationship between sensitivity and chemical gradient

Electron beam (EB) lithography used for mask and mold fabrication is an indispensable technology in the lithography used for high-volume production of semiconductor devices. With the reduction in the critical dimensions of semiconductor devices, the requirement for EB lithography also becomes severe. In this study, the feasibility of single nano patterning using EB lithography with a chemically amplified resist process was investigated. The latent images of line-and-space patterns with a 7 nm quarter-pitch (7 nm space width and 21 nm line width) were calculated on the basis of sensitization and reaction mechanisms of chemically amplified EB resists. Simulations indicated that the line-and-space patterns with 7 nm quarter-pitch can be resolved with line edge roughness of 0.9–1.9 nm with a sensitivity of 270 µC cm−2 using a 3 nm electron beam.

Equivalent Circuit Model of Semiconducting Single Walled Carbon Nano Tube based Bulk Hetero Junction Organic Solar Cell in Comparison with Experimental Results

In this paper, the characteristics of organic bulk heterojunction solar cells have been designed and modeled using MATLAB R2010a version. Here, organic solar cell is considered as a diode and an equivalent circuit is developed with series and shunt resistances to obtain the I-V characteristics of the model. Non-linear equations are obtained in by solving the equivalent circuit model. These non-linear equations are solved using Newton-Raphson method. The theoretical results thus obtained are compared with practical results and an observation made is that are theoretical results are close to the results obtained from fabricated structure.

On-demand electrostatic coupling of individual precharacterized nano- and microparticles in a segmented Paul trap.

We present a novel versatile method for one-by-one coupling of single nano- and microparticles. The particles are levitated in a segmented linear Paul trap, which is ideal for fast particle characterization and assembly of two or more preselected particles by electrostatic attraction. The final compound particles remain in the trap or can be deposited on other structures. We present the assembly protocol with a theoretical background of particle stability. Results for different particle combinations showing electromagnetic coupling are presented as well as a method for the deposition on optical fibers.

Broadband linear high-voltage amplifier for radio frequency ion traps.

We developed a linear high-voltage amplifier for small capacitive loads consisting of a high-voltage power supply and a transistor amplifier. With this cost-effective circuit including only standard parts sinusoidal signals with a few volts can be amplified to 1.7 kVpp over a usable frequency range at large-signal response spanning four orders of magnitude from 20 Hz to 100 kHz under a load of 10 pF. For smaller output voltages the maximum frequency shifts up to megahertz. We test different capacitive loads to probe the influence on the performance. The presented amplifier is sustained short-circuit proof on the output side, which is a significant advantage over other amplifier concepts. The amplifier can be used to drive radio frequency ion traps for single charged nano- and microparticles, which will be presented in brief.

Solid state preparation of CdO nano-particles by thermolysis of a precursor as compacted nanosheet

A novel complex of cadmium (II) [CdL0.5(NO3)(H2O)](1), L= N,N-bis (O-hydroxyacetophenone) ethylene diamine, have been synthesized as single crystal and nano size. Compound 1 in nano size was obtained under sonochemical irradiation and has been characterized by IR, 1 HNMR spectroscopy, X-ray powder diffraction (XRD) and scanning electron microscopy (SEM). The gray single crystal of compound 1 has been synthesized by slow evaporation and characterized by IR, 1 HNMR spectroscopy. Then, Compound 1 in nano size was used as initial reagent to obtain nano-particles of cadmium (II) oxide at 673 K by direct calcination. The obtained CdO nano-particles were characterized by XRD pattern as well as SEM images.

The impact of structural relaxation on spin polarization and magnetization reversal of individual nano structures studied by spin-polarized scanning tunneling microscopy

The application of low temperature spin-polarized scanning tunneling microscopy and spectroscopy in magnetic fields for the quantitative characterization of spin polarization, magnetization reversal and magnetic anisotropy of individual nano structures is reviewed. We find that structural relaxation, spin polarization and magnetic anisotropy vary on the nm scale near the border of a bilayer Co island on Cu(1 1 1). This relaxation is lifted by perimetric decoration with Fe. We discuss the role of spatial variations of the spin-dependent electronic properties within and at the edge of a single nano structure for its magnetic properties.

Synthesis and properties of single domain sphere-shaped barium hexa-ferrite nano powders via an ultrasonic-assisted co-precipitation route

To synthesize high quality barium hexa-ferrite nano powders, an ultrasonic-assisted co-precipitation method has been used and the influences of the ultrasonic technique on the particle morphologies and magnetic properties of the synthesized barium hexa-ferrite nano powders have been investigated. The results indicated that the introduction of ultrasonic energy into the co-precipitation process promoted the composition homogeneities of the co-precipitated precursors, minished their particle sizes, and exerted the additional surface barriers between the particles, which influenced both the phase formation and particle growth-up processes during the subsequent heating treatment and altered the particle sizes, size distributions and particle shapes of the final synthesized powders. The average particle sizes of the synthesized nano powders dramatically decreased from 210nm to about 100nm as the inputting ultrasonic power increased, while the size distribution became increasingly uniform except for a few of large particles existed as the inputting power approached to a high value. The magnetization at 1.4 T of the as-synthesized barium hexa-ferrite dramatically increased and approached to the highest value of 57.9emu/g due to the elimination of multi-domain particles, the alleviation of particle adhesion and the evolution of particle shape from flake to quasi-sphere as well as the uniform particle size distribution as the ultrasonic assistance was employed, and slightly decreased because of the coarsening in particle sizes.

Design, modeling and performance analysis of carbon nanotube with DNA strands as biosensor for prostate cancer

Prostate cancer which causes panic among human beings due to deaths occurring when not detected in initial stages demands a means of detection and diagnosis. Biosensors play an important role in detection of cancer cells or molecules in blood samples or urine samples using DNA strands. In this paper, we analyze properties of Single Wall Carbon Nano Tube (SWCNT) and Multi Wall Carbon Nano Tube (MWCNT) of 30 nm length and semiconducting nature. SWCNT is suitable for biosensor applications due to its high current carrying capability. Prostate Specific Antigen present in blood sample is detected using DNA strands, in this work three different DNA strands are analyzed for its performance. Surface charge density is 23.4656 M for dsDNA strand. The simulation tool Monte Carlo from Nanohub.org is used for validation of results.

Magneto-optical spectrum analyzer.

We present a method for the investigation of gigahertz magnetization dynamics of single magnetic nano elements. By combining a frequency domain approach with a micro focus Kerr effect detection, a high sensitivity to magnetization dynamics with submicron spatial resolution is achieved. It allows spectra of single nanostructures to be recorded. Results on the uniform precession in soft magnetic platelets are presented.

Catalytic effect of carbon nanostructures on the hydrogen storage properties of MgH2–NaAlH4 composite

The present investigation describes the hydrogen storage properties of 2:1 molar ratio of MgH2–NaAlH4 composite. De/rehydrogenation study reveals that MgH2–NaAlH4 composite offers beneficial hydrogen storage characteristics as compared to pristine NaAlH4 and MgH2. To investigate the effect of carbon nanostructures (CNS) on the de/rehydrogenation behavior of MgH2–NaAlH4 composite, we have employed 2 wt.% CNS namely, single wall carbon nanotubes (SWCNT) and graphene nano sheets (GNS). It is found that the hydrogen storage behavior of composite gets improved by the addition of 2 wt.% CNS. In particular, catalytic effect of GNS + SWCNT improves the hydrogen storage behavior and cyclability of the composite. De/rehydrogenation experiments performed up to six cycles show loss of 1.50 wt.% and 0.84 wt.% hydrogen capacity in MgH2–NaAlH4 catalyzed with 2 wt.% SWCNT and 2 wt.% GNS respectively. On the other hand, the loss of hydrogen capacity after six rehydrogenation cycles in GNS + SWCNT (1.5 + 0.5) wt.% catalyzed MgH2–NaAlH4 is diminished to 0.45 wt.%.

Performance modeling and analysis of carbon nanotube bundles for future VLSI circuit applications

In this work, we have presented a comprehensive analysis of the performance of copper (Cu) and existing carbon nano tube (CNT) bundle structures (i.e. SWCNT, DWCNT and MWCNT) across nanometer technology nodes like 45, 32, 22 and 16 nm at local, intermediate and global level interconnects. Double walled carbon nano tubes (DWCNTs) and multi walled carbon nano tubes (MWCNTs) are modeled like simple single walled carbon nano tube (SWCNT) equivalent model with high accuracy. The analytical closed form delay expressions for SWCNT, DWCNT and MWCNT bundles have been found out. It has been observed that sparse SWCNT bundle interconnects show about 50 % performance improvement for 20 $$\upmu $$ μ m long local level interconnects over Cu in 16 nm technology node, whereas the performance advantage numbers for MWCNT and sparse DWCNT bundles are 50 and 35 % respectively. For 200 $$\upmu $$ μ m long intermediate level interconnects, the performance advantage numbers are 85, 80 and 75 % for dense SWCNT, MWCNT and dense DWCNT bundles respectively in 16 nm node. For 10 mm long global level interconnects, the performance advantage numbers are 85, 85 and 75 % for dense SWCNT, MWCNT and dense DWCNT bundles respectively in 16 nm node. It is also observed that the performance numbers improve with scaling for all levels of interconnects. It is also shown that the ratio of delay of CNT bundles and Cu for various levels of interconnects agree well with the existing work.

Mechanisms of formation of sub- and micrometre-scale holes in thin metal films by single nano- and femtosecond laser pulses

Mechanisms of formation of sub- and micrometre-scale holes in thin silver and chromium films of variable thickness by tightly-focused single nanosecond IR laser pulses with fluences in the range of are studied by means of optical and scanning electron microscopy. At the minimal fluences above , the micrometre ( in radius) holes are produced in these films, accompanying the lateral heat conduction in the film during the pump laser pulse, cavitation at the metallic/glass interface and subsequent explosive removal of the molten film. At the fluences of much larger ( in radius) holes are formed in the film as a result of its heating by the erosive surface microplasma through the lateral heat conduction in the film during the plasma lifetime of the order of a few microseconds. Finally, at the maximal fluences (well above ), the sub-millimetre holes were produced in these films by intense shock waves, generated in the erosive microplasmas. The comparative analysis of the formation mechanisms for sub- and micrometre-scale holes in the same thin metal films by the single nano- and femtosecond laser pulses is provided.

A study of interaction potentials for H 2 adsorption in Single Walled Nano Tubes: a possible way to more realistic predictions

A comparative analysis of interaction potentials, classified according to the parametrization method, namely Lorentz-Berthelot rules, semi-empirical or ab initio calculations, found their energy depths to scale, respectively, to ca 30K, ca 40K, and ca 60K. We draw the Potential Energy Surfaces (PESs) for a hydrogen probe molecule inside a Carbon Nano-Tube (CNT): it is shown that the adsorption energy increases with the hard radius of the interaction potential and decreases as the CNT pore enlarges. This is valid just for low-medium pressures, when hydrogen repulsions are negligible. If not, adsorption is driven by H2-H2 hard radius despite all other parameters. Monte Carlo (MC) simulations, following the Gibbs Ensemble (GE) in high density conditions, confirm that the thermodynamic equilibrium of an order-disorder phase transition show no changes throughout any of the studied potentials. We also analyse, in the Grand Canonical (GC) ensemble, the geometric and structural characteristics of square lattice bundles of Single Walled Nano Tubes (SWNTs) with regard to their influence on adsorption storage. To do so, we develop a method for independently simulate inner or outer adsorption in infinitely long nanotube lattice systems. Our results suggest a pressure range for convenient H2 storage and enlighten the influence of CNT size on adsorption performance. In addition, larger CNTs are capable to host further hydrogen layers, but only at very high pressures.

Preparation and mechanism of nano mullite powders from kaolin via open hydrothermal process.

Nano mullite powders have been synthesized from calcined kaolin via open hydrothermal process. The powder product was characterized by X-ray diffraction (XRD) analysis, scanning electron microscopy (SEM), transmission electron microscopy (TEM) with selected area electron diffraction (SAED) analysis. The results indicated that single phase puncheon-shaped nano mullite with about 140-360 nm in length and 50-80 nm in diameter is produced when synthesized in 4 mol/L NaOH solution at 100 degrees C for 4 h. The grain size of mullite decrease slightly with increasing reaction time from 0 h to 4 h. In addition, nuclear magnetic resonance (NMR) analysis confirms presence of Al3+ during the whole reaction process, which indicates that there is an absence of growth units of mullite in the open hydrothermal system and the mullite precursor mainly underwent a solution process during open hydrothermal treatment.

Experiment and Prediction on Thermal Conductivity of Al2O3/ZnO Nano Thin Film Interface Structure

We predict that there is a critical value of Al2O3/ZnO nano thin interface thickness based on two assumptions according to an interesting phenomenon, which the thermal conductivity (TC) trend of Al2O3/ZnO nano thin interface is consistent with that of relevant single nano thin interface when the nano thin interface thickness is > 300 nm; however, TC of Al2O3/ZnO nano thin interface is higher than that of relevant single nano thin interface when the thin films thickness is < 10 nm. This prediction may build a basis for the understanding of interface between two different oxide materials. It implies an idea for new generation of semiconductor devices manufacturing.

Preparation and Performance Characterization of Soft Polymer Composites as a Function of Single and Mixed Nano Entities

Soft polymer composite (SPC) was prepared by mixing a polyvinyl alcohol (PVA) host system with conducting carbon black (CCB) as a single nano entity (SNE) and CCB+Montmorillonite (MMT) clay as mixed nano entities (MNE). The modified crystalline phase to amorphous exhibits the impact of filler. The destroyed crystalline phases are also evident from XRD spectra where interplanar distance decreased. Addition of MNE resulted in inhibition of foreign bond formation and also prevented stretching and bending of substrate molecules, which were detected by Fourier Transform Infrared (FTIR) spectroscopy. The morphology of SPC was studied by optical and scanning electron microscopy (SEM). Improvement of glass transition temperature (Tg), Young's modulus and AC conductivity was observed as a function of SNE and MNE loading.

Tunnel conductivity switching in a single nanoparticle-based nano floating gate memory

Nanoparticles (NPs) embedded in a conductive or insulating matrix play a key role in memristors and in flash memory devices. However, the role of proximity to the interface of isolated NPs has never been directly observed nor fully understood. Here we show that a reversible local switching in tunnel conductivity can be achieved by applying an appropriate voltage pulse using the tip of a scanning tunnelling microscope on NPs embedded in a TiO2 matrix. The resistive switching occurs in the TiO2 matrix in correlation to the NPs that are in proximity of the surface and it is spatially confined to the single NP size. The tunnel conductivity is increased by more than one order of magnitude. The results are rationalized by a model that include the charge of NPs that work as a nano floating gate inducing local band bending that facilitates charge tunnelling and by the formation and redistribution of oxygen vacancies that concentrate in proximity of the charged NPs. Our study demonstrates the switching in tunnel conductivity in single NP and provides useful information for the understanding mechanism or resistive switching.

短径1.0 mm の破裂極小前交通動脈瘤に対して1 本のTarget nano coil で塞栓術を施行した1 例：テクニカルノート

短径1.0 mm の破裂極小前交通動脈瘤に対して1 本のTarget nano coil で塞栓術を施行した1 例：テクニカルノート

Thermoluminescence Studies on Sr2SiO4 Nano Powder

Strontium silicate (Sr2SiO4) nano phosphor was synthesized by low temperature solution combustion technique using citric acid and glycine fuels. The obtained products were characterized by Powder X-ray Diffraction (PXRD), Fourier Transform Infrared Spectroscopy (FTIR) and PXRD confirms the formation of single phase monoclinic and orthorhombic Sr2SiO4 nano phosphor. Thermoluminescence (TL) of Sr2SiO4 nano phosphor exposed to 60Co gamma irradiation in the dose range 1- 6Gy has been studied. A single well resolved glow peak was obtained at 175°C for citric acid and at 180°C for glycine fuel respectively. The kinetic order (b), activation energy (E) and frequency factor (S) are calculated by Chen's modified peak shape method.These results show the nanocrystalline phosphor of Sr2SiO4 is suitable for radiation dosimetry.

Resist material design for next-generation lithography as it moves toward single nano patterning

Resist material design for next-generation lithography as it moves toward single nano patterning