High Power Optical Microscope Research Articles

β-HMX was prepared by hydrothermal method

ABSTRACT The conversion of α-HMX to β-HMX was studied by the hydrothermal method, that is, when the solvent is deionized water, α-HMX can be converted to β-HMX. It was confirmed to be β-HMX after being characterized by mid-infrared spectroscopy, and its crystal form was further observed by high-power optical microscope, which was consistent with the infrared characterization results. The method is simple to operate, green and safe, reduces the production cost, and also solves the problem of traditional transcrystallization waste liquid treatment.

Immediate intervention effect of dielectric barrier discharge on acute inflammation in rabbit’s ear wound

Acute inflammation is an anti-injury stress response which is beneficial to the human body. However, if the duration of acute inflammation is prolonged in specific people, such as critically ill patients and people with low resistance, it will worsen the disease and increase complication rates. Most medical researchers are committed to finding an effective method to shorten the duration of acute inflammation. The purpose of our work is to shorten the duration of acute inflammation in a rabbit’s ear wound by dielectric barrier discharge (DBD) low temperature plasma. The distribution and quantity of inflammatory cells in the rabbit’s ear wound treated by plasma were studied and calculated by using a high power optical microscope and Image J software. The reactive species of plasma were characterized by optical emission spectroscopy. The results showed that the number of inflammatory cells decreased from 2312.17 ± 242.52 to 880.17 ± 89.08 after plasma treatment for 3 min. In addition, plasma has a coagulation effect on the rabbit’s ear wound. Our results indicated that DBD low temperature plasma could be an effective tool to decrease the inflammatory response time and the inflammation was further alleviated with increased treatment time.

Investigation of erosion of stainless steel by two-phase jet impingement

The study has been conducted to assess the performance of 304, 316 and the effect of various working conditions under high velocity jet impingement in various types of media containing particles in normal water. Mass loss per unit area vs. exposure time is used to evaluate the erosion rate of the stainless steel. The surface morphologies before and after the erosion tests are observed by High-power optical microscope and scanning electron microscopy. The results show that particle concentration and particle size have significant effects on the mass loss of stainless steel. In addition, the type of particles and steels do effects on it. The maximum erosion rate is found to occur in the testing duration around 12–15 h and the erosion mechanism for different impact angle is obviously different. Using Finnie's cutting model, the calculation result agrees well with the experiment results and demonstrates that both target materials wear follow a linear relationship with the kinetic energy of impinging particles.

Direct evidence of lipid translocation between adipocytes and prostate cancer cells with imaging FTIR microspectroscopy

Various epidemiological studies show a positive correlation between high intake of dietary FAs and metastatic prostate cancer (CaP). Moreover, CaP metastasizes to the bone marrow, which harbors a rich source of lipids stored within adipocytes. Here, we use Fourier transform infrared (FTIR) microspectroscopy to study adipocyte biochemistry and to demonstrate that PC-3 cells uptake isotopically labeled FA [deuterated palmitic acid (D(31)-PA)] from an adipocyte. Using this vibrational spectroscopic technique, we detected subcellular locations in a single adipocyte enriched with D(31)-PA using the upsilon(as+s)(C-D)(2+3) (D(31)-PA): upsilon(as+s)(C-H)(2+3) (lipid hydrocarbon) signal. In addition, larger adipocytes were found to consist of a higher percentage of D(31)-PA of the total lipid found within the adipocyte. Following background subtraction, the upsilon(as)(C-D)(2+3) signal illuminated starved PC-3 cells cocultured with D(31)-PA-loaded adipocytes, indicating translocation of the labeled FA. This study demonstrates lipid-specific translocation between adipocytes and tumor cells and the use of FTIR microspectroscopy to characterize various biomolecular features of a single adipocyte without the requirement for cell isolation and lipid extraction.

レーザ光散乱法によるＳｉウエハ表面上の超微小欠陥計測

We have been developed a laser light scattering detector system for the observation of a fine defect on a bare silicon wafer surface. The argon ion laser beam with a single wavelength of 488 nm is turned into a scanning beam through a x-y deflection mechanism, and focused to a small spot by a long focus lens onto the wafer surface at oblique incidence angle of 76 degrees. The system combines a cooled CCD detector and ultramicroscopic technique. The light scattering by the defects on the wafer surface is detected by the high power optical microscope equipped with a 12-bit cooled CCD camera at the surface-normal direction of the wafer. The long exposure and high dynamic range capability of the system allows images with both high sensitivity and high signal to noise ratio to be produced. The light scattering intensity from Si wafer surface depends on the Si wafer samples supplied by corporation. The entire surface of mirror-polished wafer contains micro-roughness and micro-scratches. Micro-roughness constructs a speckle pattern, and the average intensity depends on the magnitude of micro-roughness. The image of the micro-scratch strongly changes with the angle between the incident laser beam and the micro-scratch. The most sharp image is constructed at the angle of 90 degrees. The theoretical estimation of averaged width and depth of the micro-scratches are the order of nanometer, respectively.

Evidence for phosphoprotein microspheres in bone.

Bone sialoprotein and osteopontin are 'bone-specific' phosphoproteins, but their function is uncertain and their ultrastructural associations remain unclear. Insight into their role was sought by special attention to their general distribution and specific morphology under the high-power optical microscope. Their extracellular staining characteristics were examined in cryosections of adult rat skeletal tissues using two immunohistochemical methods. The two proteins were clearly evident in immature woven bone of endochondral and intramembranous origin (although cartilage was negative, even when calcified). In mature lamellar bone, bone sialoprotein remained ubiquitous, while osteopontin was confined to cement lines and other relatively discrete sites of past and present resorption activity, particularly near blood vessels. In neither case was the distribution of the stain structureless and diffuse. Invariably (except when non-specific), it was sharply defined and had the form of microspheres measuring approximately 1 microm in diameter. In both immature and mature regions, these objects appeared in sheets, chains or groups in a pattern that was evidently coincident with a similar structural arrangement found within the inorganic phase of bone. It was concluded that phosphoproteins are not randomly located throughout the collagenous matrix but are apparently integral to calcified microsphere populations, and it is suggested that these structures are well placed to control the chemical state of the mineral over their surfaces and influence remodelling.

Nanofabrication with a scanning tunneling microscope using chemical vapor deposition

For the past few years we have made transport measurements of pure nickel wires made by decomposing nickel carbonyl with the electrons from a scanning tunneling microscope (STM), which is a form of chemical vapor deposition (CVD). The need to align the tip with four micron-size contact pads resulted in a design incorporating a non-UHV scanning electron microscope (SEM), and a concomitant low throughput of samples. Nonetheless, we have continued to reduce our wires’ dimensions and improve their quality; we show these results and discuss the primary factors governing line quality. To improve throughput and reliability further, we have finished a novel design that utilizes a high power optical microscope instead of a SEM. Two key features of this design are a very compact x–y positioner and a custom window welded directly on the side of the chamber. The positioner is built into a standard fine-screw tripod. It provides over 150 μm of orthogonal motion by tilting a 0.25 in. ball bearing that holds a 0.188 in. ball bearing in an off-center position. The 2 in. sapphire window, which protrudes into the vacuum chamber, makes it possible to have the tip as close as 6 mm to the atmosphere side. This gives an excellent view of the whole STM and allows us to use a 40× (or 20×) objective lens with a 14 (or 19) mm working distance. The extra distance is important for viewing the sample from different angles and makes it possible to place the tip over any desired feature on the surface. We present results from the new STM demonstrating this capability.

Imaging and analysis of submicron single-crystal aluminum whiskers in Al/Cu/Si deposited films

The formation of stress-relieving hillocks, also referred to as single-crystal whiskers is a well-known occurrence in the preparation of metallic thin films. In the manufacture of Application Specific Integrated Circuits, devices at the wafer level are often processed through the first metallic thin film process, coated with a plasma enhanced oxide (PEO), then stockpiled either at the manufacturer's site or the customer's to await final option-level programming. Whisker growth has been detected on wafers retrieved from the stockpile inventory. This paper describes the techniques employed for initial detection, subsequent sample preparation, and the composition analysis of submicron diameter whiskers in Al/Cu/Si thin films on inventoried product wafers.First indications of whisker growth are increased surface defect levels observed during high power optical microscope sample inspection. Typical appearance of the whiskers, as viewed with an optical microscope, are shown in Figure 1. Structures thought to be surface particles are later imaged in the SEM and confirmed to be oxide-covered whiskers, as shown in Figure 2. Imaging of the nonconductive oxide layer is accomplished via a Field Emission SEM.

Diffusion in Solids via Nuclear Track Analysis

Nuclear track analysis has been used to follow the diffusion of melted lithium hydroxide in pellets of aluminum oxide as a function of temperature and time. α particle tracks, created by thermal neutrons on an allyl diglycol carbonate monomer film, are visible under a high‐power optical microscope after chemical etching in a sodium hydroxide solution. The number of tracks present at various depths within each pellet is proportional to the concentration of lithium hydroxide. Using a one‐dimensional diffusion model with appropriate boundary conditions, values of the lithium hydroxide diffusion coefficient in the porous pellet have been determined. The diffusion coefficients, as well as their temperature dependency, are consistent with expectations for this type of system and it is concluded that nuclear track analysis is a viable technique for solid‐state diffusion studies in appropriate materials.

Magnetic properties of asbestos fibers

It is now well known that inhalation of asbestos fibres can cause a number of severe health problems, including bronchial carcinoma and mesothelioma. Exposure of workers to contaminated atmospheres is strictly controlled and Control Limits have been published defining the maximum concentration of airborne fibres. The values have recently been revised and now depend on type of asbestos fibre as well as concentration. The current method of measuring fibre concentration involves examining an exposed filter pad with a high power optical microscope. This technique is extremely laborious, is of limited accuracy and cannot distinguish between different types of asbestos fibres. A recently developed method, which considerably improves the accuracy of analysis, involves orientation of fibres in a strong magnetic field. In the present work, the orientation of amosite fibres has been measured as a function of magnetic field strength. Results indicate that fibres in the range 5 μm to 20 μm have ferro - magnetic properties and the magnetic moment of individualfibres has been predicted. An analytical technique based on this work has recently been patented and should distinguish between fibre types as well as accurately predicting the airborne concentration of asbestos fibres.

Analysis of Integrated Circuits on the Scanning Electron Microscope

The SEM plays an important role in the performance of failure analyses of Integrated Circuits. As the complexity and density of electrical functions increases on the silicon chip, the more it is nescessary to analyze the detailed characteristics of the failed device. The types of failures of interest are those that have marginal or catastrophic performance characteristics and show no obvious visual defects.Three aspects of the SEM capabilities will be discussed.Standard high power magnification operationVoltage Contrast mode of operationEmission X-ray analysis operationVarious physical characteristics of an Integrated Circuit can be viewed on the SEM. These characteristics are difficult to view on a high power optical microscope due to the depth of field limitations. These characteristics include the following.Oxide stepsMetalization profile over oxide stepsWire bond analysisEtched metalization characteristicsThe Voltage Contrast mode of operation allows direct visual observation of electrical activity on the surface of the silicon chip.

Automatic focusing of an optical system by extremum control

A method is described for automatically focusing a high-power optical microscope using an extremum controller. The principle used is that of maximising the amplitudes of certain high-frequency components of a signal derived by scanning the object. The optimum bandpass filter required in selecting these frequency components is derived on the basis of expected power spectra, and the reasons for deviating, somewhat from this optimum are explained on the basis of the statistical variations in harmonic amplitudes of practical objects. A practicable system employing a peak-holding controller is described, in which the average hunting excursion about focus is less than the normally accepted depth of focus of the optical system.

The effect of aggregation and liquid penetration on the viscosity of dilute suspensions of spherical particles

Using Brinkman's method of extending Einstein's relation for the viscosity of very dilute suspensions an equation has been derived which takes into account permanent aggregates and liquid penetration effects. Experiments with uniform particle size latex indicated that appropriate ultrasonic irradiation decreases the viscosity, and this is reflected in a change in the degree of aggregation as measured with a highpower optical microscope. An analysis of literature data indicated that permanent aggregates are present in most if not all experiments and they interfere with the detection of any possible particle size or size distribution effects in dilute suspensions.