Types of Scanning Electron Microscopes

How you can meet a range of scanning electron microscope specifications

The worlds of quality control and failure analysis are getting more complex and demanding.

Smaller and more complex samples now require thorough analysis to meet increasingly strict product specifications. You now need comprehensive information with nanoscale resolution to make sure you don’t miss a thing. What’s more, you’re expected to work to increasingly tight deadlines.

It’s a complex undertaking and one machine is up for the job – the scanning electron microscope (SEM).

Today’s SEMs are superior quality control and failure analysis machines, compared to their predecessors and optical microscopy tools.

SEMs provide higher resolution and magnification and a better depth of field than an optical microscope. They also provide comprehensive information, helping you to analyze the morphology, topography and chemical composition of your samples with ease.

If your SEM includes a broader range of detectors, you can also reveal a sample’s molecular composition (Raman), impurities and optical properties (cathodoluminescence) and crystallographic information (electron backscatter diffraction).

Modern SEMs are optimized for high throughputs, ease-of-use and measurement consistency for your quality control and fault analysis applications. Many use automation and other intuitive user interfaces to provide a solid user experience.

There are plenty of SEM options available. Your choice of instrument often comes down to your target applications and your current facilities. Let’s look at some key considerations now.

An SEM can achieve sub-nanometer resolutions and magnifications and depths of field up to 300 times better than an optical microscope. SEM resolution can be anywhere between less than one nanometer and up to tens of nanometers.

SEM resolution is an important consideration because an instrument’s cost and complexity will increase with its resolution. Resolution also affects the available applications:

• Less than one nanometer – suitable for nanoscale characterization and manipulation of nanostructures.
• Two nanometers – suitable for micro- and nanoscale characterization of topography, composition and phases.
• Three nanometers – suitable for analysis of microstructures.
• 100 nanometers or higher – suitable for quantitative compositional analysis.

Typical floor model SEMs can achieve resolutions of the order of 1 to 20 nanometers. Some SEMs are even capable of sub-nanometer resolutions. Our Verios SEM is capable of a resolution of 0.6 nanometers at 30 kV, for example, and our Apreo SEM is capable of 0.9 nanometers at 1 kV.

A desktop SEM can typically achieve resolutions of tens of nanometers. However, the Phenom Pharos SEM features a field emission gun source, and is capable of resolutions below three nanometers.

Traditionally, SEMs need a dedicated room or area in a lab, which is isolated from vibration and other thermal, electrical and acoustical disturbances. As such, footprint is a major consideration for many lab managers.

Our entry-level and environmental floor-model SEMs are ideal for multi-user laboratories working across both quality control and failure analysis applications, offering high stability and ease of use.

The Thermo Scientific Prisma E and Thermo Scientific Quattro environmental SEMs, for example, are versatile machines, making them the ideal choice if sample flexibility is a priority. Using their low vacuum modes, you can achieve high throughputs and easily analyze charging, outgassing or otherwise difficult samples.

At Thermo Fisher, we also provide a range of Desktop SEMs. These are easy-to-use and highly diverse instruments, enabling a fast time to image – plus, they have a smaller footprint, compared to floor model SEMs.

SEMs are versatile instruments, which are capable to analyzing a vast range of samples and materials. For each sample, the right combination of settings is required to optimize the results of your analysis.

At Thermo Fisher Scientific, we provide a vast range of SEMs, many of which are tailored to specific sample types.

Our ParticleX range, for example, targets specific chemical analysis applications, including Phenom ParticleX Steel Desktop SEM, Phenom ParticleX TC (Technical Cleanliness) Desktop SEM, and Phenom ParticleX AM (Additive Manufacturing) Desktop SEM. The Phenom Perception GSR Desktop SEM also provides SEM EDX gunshot residue analysis.

Within the field of material science, Thermo Scientific Axia ChemiSEM is a flexible, easy-to-use SEM EDS instrument, which provides instantaneous and quantitative elemental analysis.

We also offer a range of versatile tools, where our Thermo Scientific Prisma E and Thermo Scientific Quattro SEMs are the ideal choice if sample flexibility is a priority as you can image a sample in its natural state.

Thermo Fisher Scientific is dedicated to producing analytical SEMs that are ideally suited for your specific needs. We offer a range of versatile tools. To find out more, click here to request a budgetary quote.