Scanning Electron Microscope Lab

Head of the Laboratory: Dr. Igor Lapsker
3-5026619 (972)
building 8, room 108
3-5026619 (972)

The Science Department houses the Scanning Electron Microscope with Energy Dispersive
Spectrometr (SEM-EDS) STEREOSCAN 430i, installed in 1994.
The SEM laboratory at the HIT is an educational, research and service unit. The SEM laboratory provides service and training in scanning electron microscopy and energy dispersive spectroscopy. This is accomplished by means of graduate level courses in scanning (SEM) as well as training in the use of all instrumentation. Trained staff will prepare specimens and assist in the viewing of samples and assist in the writing of reports. The SEM is available for outside
grant and contract work.

Major equipment consist of a state-of-art analytical system composed of STEREOSCAN 430i SEM equipped for X-ray analysis ( EDS ) and digital, high resolution imaging at 20 kV.
Technique Description

One of the most outstanding features of the SEM-EDS is that it allows elemental analysis and observation from an ultra microarea to a wide area on the specimen surface without destroying the specimen. This feature is very important in fields of research including electronics and material sciences, chemistry and physics, biology and medicine, industrial engineering.Scanning Electron Microscopy (SEM) produces detailed photographs that provides important information about the surface structure and morphology of almost anykind of samples.

In SEM electron beam is scanned across a sample's surface. When the electrons strike the sample, a verity of signals which produces an sample's elemental composition. This SEM-EDS is a major tool for qualitative and quantitative analyses that are performed by bombarding a finely focused electron beam (electron probe) on the specimen, and measuring the intensities of the characteristic X-ray emitted. The SEM-EDS has the LINK ISIS computer automation system to enable automatic analysis by adding a computer to program control the electron optical system and energy analyzer. LINK has the automatic analyses program and can be scheduled for different measurement programs, calibrations, scanning, image analyses, ZAF correction, and other applications.

The three signals which provide the greatest amounts of information in SEM are the secondary electrons, backscattered electrons and X-rays.

Secondary electrons are emitted from the atoms occupying the top surface and produce interpretable image of the surface. The contrast in the image is determined by the sample morphology. A high-resolution image can be obtained because of the small diameter of the primary electron beam.

Backscattered electrons are primary electrons which are "reflected" from atoms in the solid. The contrast in the image produced is determinate by the atomic numbers of the elements in the sample. The image will therefore show the distribution of different chemical elements in the sample. Because these electrons are emitted from a depth in the sample, the resolution in the image is not as good as for secondary electrons.

Our facilities
Our facilities
Electron Microscope - STEREOSCAN 430i with Energy Dispersive Spectrometer - LINK ISIS
Sputter and Carbon Coater from SPI
Zip Driver - IOMEGA
Optical Microscopes
Image Processing
Uses of the Microscope

For many graduate students and faculty members, the SEM-EDS is a perfect tool for their fields of research.
Other users: Israel Electricity Company, Telrad, Bezeg, Sytex and other academic and commercial organizations

Typical Current Projects

Quantitative analysis for superconductors materials.

X-ray mapping of trace elements in superconductors.

Study topography and inclusions in different materials after wear
SEM imaging and elemental analysis and photography electronics, material science, biology, and other applications.

Quantitative analyses of artificial crystals, alloys, ceramics, semi and super-conductors, optical fibers and other materials for physics, chemical, electronic and material sciences.

Distance learning
Specimens Preparation Samples for SEM imaging and analysis consist of materials that are stable in a vacuum and under a high voltage electron beam. Specimens for analyses must be fine polished (or naturally have a flat surface).

For SEM-EDS analyzing non-conductive samples must be coated with thin carbon layer, that is also available in SEM-EDS Laboratory by SPI Coating System . For SEM imaging we use a gold plating by SPI Sputter Coater.

Specimen mounts can be a common thin section, four inch diameter rounds, cylinders or other appropriate mounts, or irregular object with maximal diameter 90 mm and 25 mm thickness.
Data storage Storage of the output is available on IBM PC onto hard disk, floppy disks, or disk-on-key.

Literature We houses some books with up to date works on Electron Microscopy and X-ray Microanalysis thematic.