Scanning Electron Microscopy (SEM) Analysis Services

Scanning Electron Microscopy

Scanning electron microscopy (SEM) is a surface analysis technique frequently used in material testing labs to identify surface features of sub-micron size particles. It is best suited for the analysis of surface fractures, surface contaminants, microstructures, spatial variations in chemical compositions, and crystalline structures. It uses a focused beam of electrons, which is reflected or knocked off the surface or near-surface of the sample to generate high-resolution images. With the working scales in materials getting smaller in industries like microelectronics, SEM has far-reaching applications like semiconductor inspections, microchip assembly, failure analysis, quality control, etc.

In the scanning electron microscope test, electron-sample interaction generates secondary electrons (SE), backscattered electrons (BSE), and characteristic X-rays. SE and BSE detectors are used to capture these interactions to visualize the samples’ morphological and topographical information in the laboratory. BSE images are also used for the rapid discrimination of the phases in multiphase samples. An Energy Dispersive X-ray Spectroscopy (EDS) detector within SEM is used in the testing labs to detect the characteristic X-rays and provide qualitative and quantitative elemental analysis of the sample. Environmental SEM (ESEM) is another variant of the scanning electron microscope test available for analyzing the samples containing water or other volatile substances. 2D elemental mapping and 3D reconstruction of samples are available with FIB-SEM technology.

In order for SEM samples to resist the high vacuum conditions and the high intensity electron beam, they must be tiny enough to fit on the specimen stage and may need specific processing to improve their electrical conductivity and stability. Typically, a conductive adhesive is used to fix samples rigidly on a specimen holder or stub.

SEM is not a camera, and unlike a CCD array or film, the detector does not continuously create images. The resolution is not constrained by the diffraction limit, the fineness of lenses or mirrors, or the detector array resolution, as it is in an optical system. The SE detector is fist-sized and only senses electricity; the focusing optics may be large and coarse.

In contrast to SPMs, SEMs do not inherently produce 3D pictures. However, by combining SEM with the below methods, 3D data can be obtained:

• 3D SEM reconstruction from a stereo pair
• Photometric 3D SEM reconstruction from a four-quadrant detector by “shape from shading”
• Photometric 3D rendering from a single SEM image
• Inverse reconstruction using electron-material interactive models
• Multi-Resolution reconstruction using single 2D File:
• Ion-abrasion SEM (IA-SEM)

Video 01: Scanning Electron Microscopy (SEM)

Scanning Electron Microscopy (SEM) Common Uses

There is a large variety of scanning electron microscope tests available for our clients based in the USA. All the tests are done in the best-equipped testing laboratory for utmost client satisfaction.

• Identification of cracks, imperfections, and contaminants on the surface of coated products
• Assessment of nanoparticles in coatings and paints
• Structural analysis of new species of microscopic organisms like bacteria and viruses
• Analysis of particle size and shape in the cosmetic formulations
• Failure analysis of integrated circuit boards
• Analysis of gunshot residue for forensic investigation
• Testing new vaccinations and medicines
• Topographical analysis of the semiconductor wafers

Advantages of SEM Tests

• Simple sample preparation as the sample does not need to be thin
• Data acquisition is rapid and in the digital form
• High resolution (up to 15 nanometers) and three dimensional (3D) images can be obtained
• Easy to operate with user-friendly interfaces

Limitations of SEM Tests

• The sample should be solid and must fit into the microscope chamber
• Electrically insulating samples need the application of an electrically conductive coating, which may result in artifacts
• EDS detector on SEM can not detect very light elements (H, He, and Li), and many instruments are unable to detect elements with atomic numbers less than 11
• SEM must be placed in an area that is free of any possible magnetic, electric, or vibration interference

Industries Utilizing SEM Tests

• Life Sciences
• Mining and Minerals
• Semiconductors
• Medical and Forensic Science
• Metallurgy
• Advanced Materials
• Beauty and Cosmetics
• Electronics
• Pharmaceuticals

More Details

• Working principle of SEM
• Limitations of SEM
• Advantages and uses of SEM