E-mail: info@elsolab.com

]]> http://www.elsolab.com/?feed=rss2&p=294 http://www.elsolab.com/?p=290 http://www.elsolab.com/?p=290#comments Sun, 07 Jun 2009 19:44:18 +0000 admin http://elsol.rct.co.il/?p=290 Societies

* Israel Science and Technology Homepage
* Israel Society for Microscopy (http://www.technion.ac.il/technion/materials/ism/)
* Israel Vacuum Society ( http://www.science.co.il/ivs/)
* Israel Society for Plasma (The IVS Plasma Division)
* Israel Physics Society (IPS or Israel Physics Directory)
* The International Union for Vacuum Science, Technique, and Applications (IUVSTA)
* AVS Science and Technology Society (Formerly American Vacuum Society)
* European Microscopy Society (EMS)
* Microscopy Society of America (MSA)

Meetings in the year 2007

SEMINAR by Dr Andreas Thiessen from SPECS

The seminar will take place on June 25 at 15:00, room 315, 3rd floor, Multidisciplinary Research Building.

“New trends and developments in surface science and materials analysis.”

It will cover the new techniques (LEEM, PEEM, electron analyzers and detectors, excitation sources,…), new frontiers in specifications (lateral resolution, energy resolution, temperature and pressure ranges and stability,…) and integration of surface analysis methods with preparation techniques (MBE, CVD, Sputtering, PLD,…) towards in-situ characterization (HP XPS, HP STAM, in-situ electrochemistry, in-situ device analysis,..)

Contact: Dr Jaime Gordon Listokin

El-Sol Technologies Ltd., EXPERTS IN SURFACE SCIENCE
Microscopy - Ultra High Vacuum - Scientific Instruments
Sales - Service - Maintenance - Support
Industrial Research and Quality Control
Independent Microanalytical - Materials Laboratory

Tel: +972 4 6247 033 — Fax: +972 4 6247 023
E-mail: jgl@elsolab.com — Web: www.elsolab.com — Skype: elsoltech

Meetings in the year 2006

* ICEM XVI - XVI International Congress on Electron Microscopy
September 3 to 8, 2006, Sapporo Convention Center, Sapporo, Japan,
Contact: Kazuo Furuya General Secretary of JSEM
National Institute for Materials Science
3-13 Sakura
Tsukuba 305-0003, Japan

2. An Introduction to Surface Chemistry

El-Sol Microanalytical Laboratory

IS THE FASTEST AND LESS EXPENSIVE WAY TO HAVE YOUR TESTS DONE

When You Want the Fastest Fulfillment,
the Lowest Overall Prices,
and the Most Professional Service,

El-Sol Technologies is the Clear Choice!

Users in Israel and Overseas:

Industrial Quality Control Departments

Industrial R&D Departments

Governmental Institutions

Insurance companies

Power Plants

Academia

Industries: Pharmaceutical, Electrical, Aeronautical and Space, Electronic,

Microelectronics, Automotive, New Incubator Projects, Coating, Batteries, etc.

ALL OUR WORK IS DONE WITH STRICT CONFIDENTIALITY!

]]> http://www.elsolab.com/?feed=rss2&p=285 http://www.elsolab.com/?p=283 http://www.elsolab.com/?p=283#comments Sun, 07 Jun 2009 19:24:21 +0000 admin http://elsol.rct.co.il/?p=283 Various Applications of Contact Angle Measurement

Where contact angle and surface tension measurements will play the role is compiled in the following fields:

Pharmacy:
Controlled drug release, Wettability and dissolving behavior of pharmaceutical powders, tablets and capsules of various body liquids.

Printing industry:
Wettability processes are of major importance for the offset printing process. All materials involved in the process, such as paper, metal surfaces, and rubber surfaces must have a certain degree of surface tension to result in optimum printing quality. This value depends on the surface tension of printing ink and the dampening solution - respectively.

Semiconductor:
The cleanness and the surface chemical composition on pure semiconductor surfaces and treated surfaces such as nitrides or oxides are correlated to the surface energy of these surfaces, Therefore, the measurement of contact angles is a simple and fast method providing quality control in this field.

Cosmetics:
The contact angle is an important parameter for the cleaning process of shampoos and for the effectiveness of cleaning solutions.  Surface tension  is a parameter for the effectiveness of surfactant solutions. Furthermore,  it is necessary for the development of time and temperature-stable emulsions for various cosmetic products. For example: Titanium Dioxide is used as a sun blocker in sun tan creams. The development of a stable, ultra-fine dispersion of Titanium Dioxide in the sun tan emulsion can be simplified by measuring the surface free energy of the particles to be suspended and the surface tension of the liquid carrier.

Biology:
Wetting of plant surfaces by pesticides and fungicides is very important in determining the effectiveness of the pesticide and fungicide formulations.  Interaction of plant leaf and acid rain is important to know for protecting valuable corps.  Critical surface tension of cell surfaces and bacteria to implants or drug surfaces needed to be identified for curing disease or for an artificial organ implantation.

Lacquers and paints:
Measurement of hydrophobicity of lacquer surfaces, especially for the automobile body coating. Development of stable emulsions for paint’s storage shelf life also involve the interfacial tension between the particle and carrier in the paint formulation. Measurement of interaction/adhesion between paint and substrate surfaces (paper, metal, wood, plastics) is critical in the coating processes, especially for the change from solvent-based paints and lacquers to water-based systems, which usually causes a lot of problems for the coating processes.

Preservation of buildings:
Historical buildings have to be protected and preserved against pollution such as acid rain. Their surfaces have to be impregnated by silicide acid or synthetic materials.

Environment:
Sands polluted by oil can be cleaned by treatment with surfactant solutions.  The progress of the cleaning process can easily be controlled by contact angle measurements on the treated and pretreated samples.

Medical field:
Air-tightness of glass vessels containing medicinal fluid. The tightness of rubber sealing caps on glass surfaces can be predicated by surface free energy measurements. Artificial bones and artificial organs have to have a certain surface free energy to be accepted by the human body. Tubes transporting body fluids have to avoid the buildup of agglomerates. The same is the prerequisite for biomembranes.

Optics:
The wettability of contact lenses as well as the interaction and the effectiveness of cleaning solution formulation for contact lenses can be examined by contact angle measurement.

Dental materials:
The contact angle of saliva on tooth surfaces depends on the materials used in the cleaning process. Artificial material must have a certain surface tension and polarity in order to avoid deposition of bacteria and in case of transplants to ensure good adhesion between tooth and embodiment.

Paper Industry:
Like the printing industry the paper industry is involved in wetting problems. According to its use the paper has to be strongly or weakly hydrophobic or hydrophilic. A beaker made of paper must have a different surface energy than a sheet of newspaper. A juice container must have different surface energies on the outside (printability) than on the inside (liquid-resistant and microbiologically inert).

Polymers:
The interfacial tension and surface free energy of polymers and polymer blend can easily be controlled by surface tension measurement. The interfacial tension between various polymers in a polymer blend or between carbon fibers and surrounding polymer in fiber reinforced material is an important parameter for the stability of the materials.

Synthetic foils:
Corresponding to the production process and the surface treatment (chemical, plasma, and flame treatments) the composition of foils and their surface characteristics can be varied remarkably. Very often the foils have to be printable.

Textiles:
The wettability of single fiber as well as the wettability of fabrics can be determined using tensiometer and contact angle meter. Synthetic fibers are usually coated with hydrophobic materials. The degree of hydrophobicity as well as the homogeneity of the coating can be checked through contact angle measurement.

Adhesives:
The adhesion between different components of composite structures, between different materials like glass and metal, leather and fabrics, wood and paper, can be determined by contact angle measurement. Today, a wide variety of material combinations which have been connected in the past by soldering, welding and means of mechanical connection are more easily and durably connected by adhesives. The work of adhesion of two surfaces connected with adhesives, the wetting of adhesives on the substrate can be determined by contact angle measurement.

1. Description of Technique

Secondary Ion Mass Spectrometry (SIMS) is a surface sensitive analytical technique in which an energetic Argon, Cesium or Oxygen dimer ion beam sputters a sample surface and secondary ions are formed and collected into Quadrupole (in our case) mass spectrometer.

The technique is noted for exceptional sensitivity (0.1 ppm), depth profiling capability and mass range from Hydrogen (H) to Uranium (U) and lateral resolution down to micrometers or less (with Ga source).

In SIMS the sample is exposed to bombardment by the primary ions which generates a process of the release of secondary ions: Generally the primary ion penetrates the top layers of the sample and produces there a cascade of impacts. Part of this cascade is directed towards the surface and is able to detach there singular atoms or fractions of molecules. This process is called ion etching or ion sputtering. Some of this fragments have a positive or negative charge and, therefore, can be detected in a mass spectrometer. The so produced secondary ion mass spectrum is characteristic for the element distribution at the surface of the sample and gives also evidence within certain limits of the chemical state of the sample.

The particular advantage of SIMS is the very high sensitivity of the method for a number of elements, contrasted by the disadvantage that the sensitivity for one particular element depends very much on the composition of the sample. This is called the matrix effect that can reach several orders of magnitude. The matrix effect, however, can be considerably reduced by using, Cesium, Oxygen or Nitrogen for the primary ion bombardment.

As the peaks corresponding to the masses present can only occur at discrete values, the background is solely defined by the limited resolution and the background behaviour of the mass spectrometer.

SIMS is of the analysis methods described in our website the only method that allows the detection of Hydrogen (H). A further advantage of the SIMS method is the possibility of detecting isotopes so that isotope-marked samples can be investigated.

2. Sample information

* The area of interest must either be an exposed area or within about 2 microns from the surface (general work). Greater than 2 micrometer depth profile not general work
* The maximum sample size that can be accommodated: less than 1´ 1 cm.
* The minimum sample size that can be accommodated in the sample holder is limited by handling considerations.
* The regular minimal area that can be analyzed is around 10 micrometers.
* The sample must be UHV vacuum compatible.
* Conductive samples can be analyzed while non-conductive samples can in the majority of cases be analyzed as well.

3. Information Obtained

* Depth profiling: from surface up to few microns.
* Qualitative data provides identification of all elements in the periodic table starting at Hydrogen (H).
* Sensitivity: depending on element and matrix effect, ppm
* Quantitative data obtained with sensitivity factors and standards, Surface: Initially measures the top few Angstroms. However the first 200-300 Angstroms of sputtering are not quantitative; Bulk: SIMS works best after sputtering equilibrium is obtained (200-300A).
* Quantitative data obtained: limited to single crystal samples with standards.
* Element range: Hydrogen (H) to Uranium (U).

4. Statistics/Miscellaneous

* Data collection time varies (for good conducting samples) from a few minutes for a quick survey to more than 20 hours for long depth profiles and maps. Poor conducting samples increases the time for analysis (and in some cases it can be impossible to analyze the samples at all).
* The typical analysis time varies from roughly three hours to, some times, several days, depending on information needed by customer.
* The detection limit is on the order of ppm or better depending on the element and the length of time spent in data acquisition.
* Precision: The reproducibility is on the order of about 5-10%.
* Accuracy: Better than 5% with good standards.

5. Unique Capabilities of Technique

* High depth resolution with Depth profiling with sub-ppm sensitivity for many elements.
* Ability to detect Hydrogen (H)
* Mapping capabilities provide sample chemical element distribution on surface.

Secondary Ion Mass Spectrometry (SIMS) Equipement

1. Instrument

1. Model PHI-590, Physical Electronics (USA) for Surface Analysis and Depth Profiling with SIMS Attachment.
1. Primary Ion Beam - Ar
2. Minimum Beam Diameter - 200 mm
3. Maximal Ion Beam Energy - 5 KeV
4. Mass Range - 1 to 300 amu
5. Quadrupole Mass resolution - 1 amu
6. Sensitivity - depending on element and matrix effect, till ppm
2. Model: ATOMIKA 4500 DEPTH PROFILER (external service)

This is one of the best profilers for the microelectronics and the metallurgical industry

1. Primary Ion Beam: Cs+ and O2+
2. Minimum Beam Diameter - in the micrometer range
3. Ion Beam Energy - 0.2KeV to 5 KeV, FLIG Technology
4. Capabilities - Depth Profiling and Elemental Imaging
5. Mass Range - 1 to 300 amu
6. Quadrupole Mass Resolution - 1 amu
7. Sensitivity - ppm range and delta (d) doped samples

2. Sample information

* The area of interest must either be an exposed area or within about 2 microns from the surface (general work). Greater than 2 micrometer depth profile not general work
* The maximum sample size that can be accommodated: less than 1´ 1 cm.
* The minimum sample size that can be accommodated in the sample holder is limited by handling considerations.
* The regular minimal area that can be analyzed is around 10 micrometers.
* The sample must be UHV vacuum compatible.
* Conductive samples can be analyzed while non-conductive samples can in the majority of cases be analyzed as well.

Secondary Ion Mass Spectrometry (SIMS) Technique

X-ray Energy Dispersive Spectroscopy

1. Description of Technique

The scanning electron microscope (SEM) is used to analyze the surface of specimens over a wide range of magnifications. A focused beam of electrons is either scanned across the surface of a specimen to form an image or stopped on a fixed location to perform one of a variety of spectrographic or analytical functions. The interaction of the beam with the specimen results in the generation of secondary electrons, backscattered electrons, Auger electrons, characteristic x-rays, and photons of various energies.

Secondary electrons and backscattered electrons are collected by their respective detectors and their signals are amplified. These electrons are used in imaging. Secondary electrons mainly provide surface topographic imaging and backscattered electrons can form both images and supply atomic number information about the sample. Information may also be obtained as a result of the beam interjecting charge carriers into the specimen, which may be used to assess semiconductor material properties. Alternatively, the specimen’s surface potential may be measured by the “voltage contrast” method. Thus the position of a crystal defect or a p-n junction may be correlated with surface topography by comparing images obtained by different methods. Crystal perfection may be studied by electron channeling contrast, Kikuchi patterns and electron backscatter diffraction patterns.

The elemental make-up of the portion of the specimen illuminated by the beam may be determined via x-ray energy dispersive spectrometer (EDS) or wavelength dispersive spectrometer (WDS) attachments on the SEM. Utilizing a fixed beam generates an X-ray spectrum. Rastering the beam on the surface provides an elemental map of the surface.

2. Sample preparation for analysis

Little specimen preparation is needed other than assuring that the specimen’s surface is clean, free of artifacts, and conductive. Non-conducting specimens are usually carbon coated.

3. Information Obtained

Information comes from the surface and the portion of the specimen close to the surface. How close is a function of the instrument’s accelerating voltage, the composition of the specimen, and the signal in question.

* The secondary electron signal comes from the top 20 - 50 Angstroms. Utilizing very low instrument accelerating voltages for very shallow penetration, resulting in a true surface image.
* The BSE signal come from depths in the micron range and will provide elemental information arising in the entire volume of specimen involved.
* The x-ray signal used to form spectra or element maps arises in a volume within the specimen on the order of microns in depth. Both qualitative and quantitative elemental analysis is possible. All elements from B on up in the periodic table may be detected. Our Lithium drifted Silicon detector (from EDAX - USA) can be operated in a windowless mode, ECON III, allowing 100% transmission of x-rays for all elements. Due to a very low noise circuitry of the data acquisition system, and the windowless detector, the light elements B, C, N, O, F can easily be detected. EDS detectability limit is about 0.1%.

4. Statistics/Miscellaneous

* Data collection time: SEM images take about 1 min/photograph (development time), observation and adjustment of features in image (magnification needed, contrast enhancement, etc.) may take from one hour to many hours.
* Quantitative analysis and x-ray maps will take from one to many hours

Energy Dispersive Spectroscopy Equipement