Search

A tapping mode scanning probe microscopy (TM SPM) system for surface measurement in nanoscale is developed, of which the main element is a scanning probe consisting of quartz tuning fork and a long sharp tungsten tip. Quartz tuning fork is a very good resonant element with piezoelectrical characteristic, and it acts as an actuator and a force sensor simultaneously in the probe. The vertical spatial resolution of the TM SPM is up to sub-nanometer (0.11 nm) and the measuring force is in micro Newton magnitude (about 30 μN). In the scanning operation, the probe vibrates at its resonant frequency, so that the amplitude or frequency (or phase) of the resonant tuning fork is very sensitive to external forces (Its quality factor in air is about 3138). Using the TM SPM constructed by this probe, silicon samples are scanned. Their topography and phase images which indicate the surface material characteristics are reconstructed effectively with a high resolution and low destructiveness. Soft materials, such as Protein structure can also be scanned theoretically without damage. In addition, because of the using of the long sharp tungsten tip, the system has the capacity of measuring micro structures with large aspect ratio, such as large micro steps, deep micro trenches, etc.

Polarization interferometric nonlinear confocal microscope has been developed to observe a submicron size object in high contrast. The microscope succeeded in resolving the inside of a 200-nm-diameter polymeric nanoparticle. According to CTF (contrast transfer function) measurement and three-dimensional imaging with the microscope, the best spatial resolution for the microscope is 10 nm.

A wave optical calculation of the probe size of a low energy scanning electron microscope is presented. The resolution for the optimal aperture was computed and compared with results of standard approaches. The effect of deflection aberrations is also considered, and it was found to be critical for the landing energies below 5eV and fields of view larger than 100 x 100 μm2.

International audience; The design, fabrication and experimental validation of a novel near-field scanning millimeter-wave microscope (NSMM) built inside a scanning electron microscope (SEM) is presented. The instrument developed can perform hybrid characterizations by providing simultaneously atomic force, complex microwave impedance and electron microscopy images of a sample with nanometer spatial resolution. By combining the measured data, the system offers unprecedentable capabilities for tackling the issue between spatial resolution and high frequency quantitative measurements.

In this paper, we report a miniaturized laser scanning microscope. Unlike conventional microscopes, the optical fiber used here for the excitation laser and signal’s transmission largely improves our microscope’s mobility, and thus eliminates the space constraints of the sample stage. This miniaturized microscope can be motorized along XYZ axis and rotated in theta direction. Based on this modified microscope, we take images of test targets and a micrometer, and compare the resolution and signal to background ratio between its confocal and non-descanned detection modules. We also present the imaging results of Hela cells on a tilted sample stage to simulate the imaging of large and irregular samples. Therefore, this miniaturized microscope has the potential to be utilized for in vivo imaging of large animals.

Methods of determining the basic metrological characteristics of a near-field scanning optical microscope, i.e., scale factor and spatial resolution, defined as the diameter of the optical probe, are proposed. The use of the proposed method for calibration of the near-field scanning optical microscope directly in the course of measurements of the parameters of biological objects is investigated.

Recently a multi-beam scanning electron microscope (MBSEM) has been developed, which delivers 196 focused beams to a sample, each of which has around 1nA. In this article a design for an optical system is described and analyzed which can focus all these beams onto a single spot, using an array of micro electron lenses. Although each individual micro lens will be of lower quality than a single macro objective lens, a system is obtained with larger beam current than the conventional SEM. The goal set in an example design is to focus a total current of 200nA within 50nm at a landing energy of 500eV.

A four-channel Kirkpatrick-Baez microscope working at multiple energy bands is developed for multiframe X-ray imaging diagnostics at the Shenguang-II laser facility. The response to the multiple energy bands is realized by coating the double-periodic multilayers on the reflected surfaces of the microscope. Because of the limited size of the microstrips in the X-ray framing camera, the image separation is controlled by the conical angle of the reference cores during microscope assembly. This study describes the optical and multilayer design, assembly, and alignment of the developed microscope. The microscope achieves a spatial resolution of 4-5 mm in the laboratory and 10-20 mm at Shenguang-II laser facility within a 300 mm field of view. The versatile nature of the developed microscope enables the multiple microscopes currently installed in the laser facility to be replaced with a single, multipurpose microscope.

A method for measuring the scan nonlinearity of a scanning electron microscope is discussed. This method is tested using a mass-produced microscope and demonstrates good results.

A method for measuring the electron density distribution in the probe of a low voltage scanning electron microscope is described. It is shown that the focused electron probe of an S 4800 scanning electron microscope at the electron energy of 200 eV has a Gaussian shape of the electron density with the effective diameter of the probe of 20 nm.

The medium-term storage stability and reproducibility defined in the course of calibration of the scale factor of scanning electron microscopes are established with the use of an MShPS-2.0K measure. Conclusions are drawn to the effect that the dependence of the scale factor on the working distance may lead to some scatter of the measurement results and that direct comparison of the dimensions of the measured subject and a reference object obtained with the same parameters of the microscope is required to increase the measurement accuracy.

Known methods for determining the resolution of a scanning electron microscope are discussed. It is shown that none of them can unambiguously characterize the scanning electron microscope.

We report on the design and performance of a high stability scanning confocal microscope for optical microscopy at low temperatures. By scanning the beam in a cold objective lens system, we achieve wide fields of view without compromising image quality. Photoluminescence from single nitrogen-vacancy centers in high purity diamond is used to illustrate the imaging and stability performance of the microscope. © 2010 American Institute of Physics.

Limitations on the calculation of high-resolution detail in electron microscope images of defects in crystals are discussed and it is shown how images of crystals with arbitrary strain can be calculated by means of a reinterpretation of the normal dynamical equations. An alternative approach, which in some cases is preferable for numerical calculations, is the method of periodic continuation. These methods, and various approximations to them, are applied to the study of high resolution images of edge dislocations. It is shown that at the 5 A level of resolution, the column approximation is adequate for calculating the important features of weak-beam images of an edge dislocation with an extended core. However, when applied to the calculation of lattice fringes near a core, it may lead to serious error. Calculations are presented which show that, because of spherical aberration, care is required in the interpretation of lattice-fringe images near a dislocation core even for thin crystals.

In this paper cantilever detection methods of microscopy that allow to get an image of surface with high spatial resolution are discussed. The functionality of the scanning tunneling microscope and principle of its operation are analyzed. Basing on the simulated data, it is possible to show how microscope operating parameters affect the results of its measurements.

The scan nonlinearity of scanning electron microscopes is estimated with the use of a relief element with known geometric form of the profile. The mean value of the step of the test relief structure, which is determined as a test sample is moved along the scanning axis X, is measured. It is experimentally demonstrated that with a 5× magnification, the maximum relative deviation from the mean value of the step of the test structure for a given microscope does not exceed 0.4%.

Estimation of the procedural error of measurements of the geometric parameters of objects by a method involving defocusing of the electron probe of a scanning electron microscope is carried out. The procedural error is caused by the dependence of the results of measurements on the parameters of the probe. It is shown that this error may be reduced by selecting optimal parameters of the probe at which the actual measurement conditions correspond in the best way possible to the requirements of the computational model.

The operation of the Raith-150 electronic lithograph in the mode of a scanning electron microscope is examined. Sizes of the pixel and effective diameter of an electron probe are determined along both scanning directions. The parameters of a system for scanning and forming the lithograph’s electron probe compare well with those of the best scanning electron microscopes.

Valence EELS and energy-filtering TEM appear to be powerful tools to explore diverse nanoscale phenomena. The techniques enable real-time information on the band structure, bonding, dielectric and optical response and phase compositions of nanostructured materials. Furthermore, electron beam-induced excitations in the 0 to 50 eV energy loss range dominated by plasmons are sensitive to valence electron states primarily responsible for intrinsic materials properties. We used universality and scaling in relationships between the volume plasmon energy and cohesive energy, elastic moduli and hardness to derive analytical expressions for quantitative determination of the properties. Based on this approach, cohesive and elastic properties of metastable nanoprecipitates in structural alloys and hardness of diesel engine soot nanoparticles have been evaluated. Spatially-resolved plasmon spectroscopic imaging techniques offer possibilities to determine and image in situ multiple physical properties of nanoscale materials and to monitor their changes during dynamic transformations, thus establishing new capabilities for material research.

Atomic Force Microscopy (AFM) permits measurements on biological samples below the limits of light microscopy resolution under physiological environments and other controlled conditions. Consequently, AFM has become an increasingly valuable technique in cell biology. One of the most exciting advances in AFM instrumentation has been its integration with the light microscope. This permits investigators to take advantage of the power and utility of light microscopy and scanning probe microscopy simultaneously. In combining a light microscope with an AFM, scanner components must be specifically designed so that they do not adversely impact the light microscope's optical imaging capabilities. For example, an AFM-ILM (inverted light microscope) hybrid system should be fully compatible with the highest quality, off-the-shelf 0.50–0.55 NA numerical aperture (NA) OEM objectives and condensers.

Technical parameters and possible applications of an infrared scanning microscope with a spatial resolution of up to 3 µm are considered. It is shown that the device works with both array and linear photodetectors. Original PC software was designed to control the scanning process interactively and receive and process images of objects in the infrared range,.

We have developed a multi-beam scanning electron microscope (MBSEM), which delivers a square array of 196 focused beams onto a sample with a resolution and current per beam comparable to a state of the art single beam SEM. It consists of a commercially available FEI Nova-nano 200 SEM column equipped with a novel multi-electron beam source module. The key challenge in the electron optical design of the MBSEM is to minimize the off-axial aberrations of the lenses. This article addresses the electron optical design of the system and presents the result of optics simulations for a specific setting of the system. It is shown that it is possible to design a system with a theoretical axial spot size of 1.2 nm at 15 kV with a probe current of 26 pA. The off-axial aberrations for the outermost beam add up 0.8 nm, increasing the probe size to 1.5 nm.

Scanning near-field acoustic microscope (SNAM) combines the ultrasonic detection technology with scanning near-field microscopy. The main characteristic of such microscope is that the acoustic wave is produced or detected in near-field area whether ultrasonic transducer acts as generator or detector. The resolution of SNAM can reach to nanometer scale. First, two typical SNAMs, scanning electron acoustic microscope and scanning probe acoustic microscope, will be introduced in this paper. The working principle of our homemade SNAM based on a commercial scanning probe microscope will be reported, together with some recent results from this homemade SNAM.

An optical scanning near-field microscope was developed. A cryostat for obtaining low temperatures in the range of 1.8–300 K was designed. The microscope control unit and software were advanced taking into account the temperature range. A room-temperature measurement technique was refined on test aluminum gratings on glass with a period of 4 µm. An optimum size of the scan field, which makes it possible to neglect piezoceramics nonlinearities, was determined.

A Mott analyzer of the spin polarization of secondary electrons was installed in a conventional scanning electron microscope (SEM). It can be used to study the magnetic states of the surfaces of ferromagnetic objects. The first results of experiments using scanning electron microscopy with analysis of the spin directions to obtain images with magnetic contrast are presented. Problems connected with the implementation of this procedure in the case of a conventional SEM with a relatively low vacuum are discussed, and factors affecting the choice of optimal experimental conditions are analyzed.

A simple and quick method to measure the electric field distribution near a specimen using a conventional transmission electron microscope has been developed. The electric field distribution around a field emitter needle was measured to evaluate the performance of the method. It was found that this method allows us to measure the 2D distribution of electric field quantitatively with error of

A new electron diffraction microscope based on a conventional scanning electron microscope (SEM), for obtaining atomic-level resolution images without causing serious damage to the specimen, has been developed. This microscope in the relatively low-voltage region makes it possible to observe specimens at suitable resolution and record diffraction patterns. Using the microscope we accomplished 10-kV diffractive imaging with the iterative phase retrieval and reconstructed the structure of a multi-wall carbon nanotube with its finest feature corresponding to 0.34-nm carbon wall spacing. These results demonstrate the possibility of seamless connection between observing specimens by SEM and obtaining their images at high resolution by diffractive imaging.

Zusammenfassung Die Vermessung von mikro-strukturierten technischen Oberflächen ist eine aktuelle Kernfragestellung der Messtechnik. In diesem Beitrag werden 3D-Rekonstruktionsverfahren von rasterelektronenmikroskopischen Aufnahmen, insbesondere die photometrische Methode, vorgestellt. Zur Verifikation des entwickelten Modells wurde ein Rasterelektronenmikroskop mit zwei Detektoren versehen.

An X-ray microscope equipped with a multiwalled carbon nanotube (MWCNT) cathode was developed. This system has ordinary scanning electron microscopy functions available for the precise adjustment of focusing conditions including astigmatism and an alignment of an electron beam. Owing to the adoption of a transmission type, X-ray images with high magnification can be easily obtained. The diameter of an electron probe, which is one of the factors limiting a spatial resolution of X-ray microscopes, was estimated to be ca 50 nm from a resolution of obtained SEM images. X-ray images were taken as a demonstration of the X-ray microscope and clear images with a resolution higher than 700 nm were successfully obtained. Copyright © 2008 John Wiley & Sons, Ltd.

A method is presented for measuring the scan linearity in an atomic-force microscope, which uses the first derivative of the signal. The method has been tested on a standard microscope and has shown good results.

A method is proposed for calibrating a scanning electron microscope that corresponds completely to national standards providing unification of measurements in nanotechnology.

A scanning probe microscope that allows studies of electron transport—in particular, in carbon nanotubes at cryogenic temperatures—has been developed. The stiff structure of the microscope and its small transverse dimensions allow scanning to be performed in the atomic-force-microscope mode of a portable Dewar flask with a neck diameter of >40 mm without using additional vibration insulation.

We have developed a new type of microscope possessing a unique feature of observing both scanning electron and X-ray images under one unit. Unlike former X-ray microscopes using SEM [1, 2], this scanning electron and X-ray (SELX) microscope has a sample in vacuum, thus it enables one to observe a surface structure of a sample by SEM mode, to search the region of interest, and to observe an X-ray image which transmits the region. For the X-ray observation, we have been focusing on the soft X-ray region from 280 eV to 3 keV to observe some bio samples and soft materials. The resolutions of SEM and X-ray modes are 50 nm and 100 nm, respectively, at the electron energy of 7 keV.

We report on the development of a new magnetic microscope, time-resolved near-field scanning magneto-optical microscope, which combines a near-field scanning optical microscope and magneto-optical contrast. By taking advantage of the high temporal resolution of time-resolved Kerr microscope and the sub-wavelength spatial resolution of a near-field microscope, we achieved a temporal resolution of ∼50 ps and a spatial resolution of

We describe a vector scanning system to reduce charging effects during scanning electron microscope (SEM) imaging. The vector scan technique exploits the intrinsic charge decay mechanism of the specimen to improve imaging conditions. We compare SEM images obtained by conventional raster scanning versus vector scanning to demonstrate that vector scanning successfully reduces specimen-charging artifacts.

Accurate spatial measurements in a scanning electron microscope (SEM) require calibration of the magnification as a function of working distance and microscope operating conditions. This work presents the results of the calibration of an environmental SEM for the accurate spatial measurement of dimensions and areas in experiments, both for the measurement of strain in steel specimens under applied loads and the measurement of dimensional changes in timber with changes in relative humidity.

An atomic force microscope (AFM) and spectrometer combined system for in-situ thickness measurement of nano-porous alumina (PA) films is introduced. The AFM is applied to obtain the porosity of PA film, and then we calculate the effective refractive index by Maxwell-Garnett effective dielectric constant theory. The optical thickness of PA film is determined by reflective interference spectrometer. The PA film thickness can also be measured via scanning the crosssection with optical microscope and scanning electron microscope (SEM). The sample will be damaged, however, when using this method. The measurement by optical microscope is convenient, but it's hard to attain high resolution. When using SEM, the sample surface must be gilt and needs a vacuum environment. The system we developed can avoid the disadvantages of the method. It realizes non-destructive and highresolution in-situ measurement.

The modification of a commercial tapping mode atomic force microscope (AFM) into a transmission mode near-field scanning optical microscope (NSOM) is presented and polystyrene spheres in the diameter of 100 nm are used in this experiment. The detection of near-field signals is based on photodiodes with lock-in technique, and resolutions of topography and near-field signals obtained are about 10 and 20 nm, respectively. Furthermore, it is discovered that the computer-simulated near-field energy distribution profile, obtained by scanning over polystyrene spheres under illumination mode, falls within 5% range as compared with experimental values. The near-field absorption coefficient can be determined by this way. This will be a useful theoretical model to analyze the near-field transmission effect from others.

We demonstrate a special four-probe scanning tunnelling microscope (STM) system in ultrahigh vacuum (UHV), which can provide coarse positioning for every probe independently with the help of scanning electron microscope (SEM) and fine positioning down to nanometre using the STM technology. The system allows conductivity measurement by means of a four-point probe method, which can draw out more accurate electron transport characteristics in nanostructures and provides easy manipulation of low dimension materials. All measurements can be performed in variable temperature (from 30K to 500K), magnetic field (from 0 to 0.1T) and different gas environments. Simultaneously, the cathodoluminescence (CL) spectrum can be achieved through an optical subsystem. Test measurements using some nanowire samples show that this system is a powerful tool in exploring electron transport characteristics and spectra in nanoscale physics.

A novel 8-dimensional microscope with functions of microscope laser light scattering spectroscopy, 3-dimensional relief imaging, and fast micro-spectrophotometry is introduced. The applications of this multidimensional microscope to nano-material measurements are also described.