An Introduction to FIB-SEM
The behavior of materials and biological systems is often shaped by the hidden structures that lie beneath their surfaces. A crack deep within a metal, a fault in a semiconductor device, or the architecture of a biological cell can hold insights about a sample’s structure and function that surface imaging alone cannot provide. Traditional microscopy techniques each have their place in characterizing surfaces and structures. Scanning electron microscopy (SEM) delivers detailed surface information, while transmission electron microscopy (TEM) reaches atomic resolution, although it does require ultrathin specimens. However, neither SEM nor TEM alone can easily provide subsurface or three-dimensional data. Researchers therefore have turned to focused ion beam-scanning electron microscopy (FIB-SEM), which overcomes these limitations by combining precision milling with high-resolution imaging. It has since become a well-established tool across many areas that require advanced microscopy, including materials science, semiconductors, life sciences, and energy research.
What is FIB-SEM?
A FIB-SEM is a dual-beam instrument that brings together:
- A focused ion beam (FIB), which directs a stream of ions onto the sample to cut, mill, or sputter away thin layers of material.
- A scanning electron microscope (SEM), which uses a beam of electrons to produce high-resolution images of the newly exposed surface.
By combining an ion beam for material removal and an electron beam for imaging, FIB-SEM helps scientists to:
- Examine hidden structures beneath the specimen’s surface.
- Collect a sequence of images that can be reconstructed into a 3D model.
- Produce ultrathin lamellae at selected locations for TEM analysis.
- Deposit protective coatings or modify surfaces as needed.
Rather than serving a single function, FIB-SEM unites fabrication and imaging in one system, making it uniquely versatile and a powerful tool for investigating complex structures.
How Does FIB-SEM Work?
The Workflow
FIB-SEM workflows are built around a repeated cycle of milling and imaging. It typically consists of four key stages:
- Identify the region of interest
The SEM is used to visualize the sample surface and locate the exact area of investigation. Researchers can zoom in on features such as defects, grain boundaries, or regions of biological tissue that require closer examination.
- Mill with the ion beam
A finely focused beam of ions, usually gallium, is directed at the chosen site. With the adjustment of the beam current, operators can switch between fast, coarse milling for removing bulk material and gentle, fine milling for polishing delicate features, ensuring the resulting cross-section is clean and ready for imaging. - Image with the SEM
At this point, the SEM directs an electron beam across the newly exposed surface, generating contrast that highlights the sample's surface structures and microstructural features. - Repeat the cycle
Alternating between milling and imaging allows researchers to cut through the sample layer by layer. The set of acquired scans can then be assembled into a 3D reconstruction or used to prepare an ultrathin lamella for TEM analysis.
The Components Behind the Workflow
Several key components are required to make the FIB-SEM workflow possible:
- Ion source: Gallium liquid metal ion sources provide precise, stable milling.One
- Electron column: This part of the SEM generates and focuses the electron beam, producing high-resolution images that reveal surface detail and compositional contrast.
- Stage and chamber: A motorized, multi-axis stage positions the sample with nanometer accuracy, and large chambers accommodate varied specimen sizes.
- Detectors and accessories: Options such as STEM detectors, EDS for elemental mapping, and gas injection systems (GIS) expand the analytical capabilities of the FIB-SEM and support processes like protective coating and lamella preparation.
Applications of FIB-SEM
The adaptability of FIB-SEM has made it valuable across many fields:
- Materials science: Studying grain boundaries, porosity, and failure mechanisms, often using protective coatings to safeguard delicate regions of the sample during milling.
- Life sciences and neuroscience: Imaging tissues and cells in 3D, mapping neural networks, and preserving ultrastructure through cryo-FIB-SEM workflows.
- Energy and geosciences: Characterizing battery electrodes, porous rocks, and other complex materials to understand performance and degradation.
- Semiconductors and electronics: Inspecting device defects, modifying circuits, and preparing lamellae for TEM, with gas-assisted deposition enabling both shielding and microfabrication.
Advantages of FIB-SEM
FIB-SEM offers a unique set of benefits:
- High-resolution 3D imaging that reveals both surface and subsurface features, providing insights that are unavailable from conventional microscopy.
- Site-specific targeting, which allows researchers to focus on regions of interest without damaging surrounding material.
- Integrated milling, imaging, deposition, and analysis, reducing the need for multiple instruments and streamlining workflows.
- Flexibility across scientific and industrial applications, from failure analysis to biological imaging, making it versatile enough to cater to diverse research challenges.
Advancing FIB-SEM Research With JEOL Solutions
FIB-SEM has established a means of exploring beyond surface imaging and studying subsurface structures in greater detail. The
JIB-PS500i from JEOL supports these investigations with precise ion milling, seamless integration with TEM, and cryogenic options for sensitive samples. Its spacious chamber and 5-axis motorized stage accommodate diverse specimens, while integrated STEM and EDS detectors keep imaging and analysis within a single platform.
For researchers working with frozen hydrated or otherwise delicate materials, the
CRYO-FIB-SEM CryoLameller adds a dedicated cryogenic workflow. Liquid-nitrogen cooling, cryocooled transfer, and controlled low-temperature milling help maintain sample integrity and enable the production of high-quality TEM lamellae. Together, the JIB-PS500i and CRYO-FIB-SEM CryoLameller provide complementary approaches for conventional and cryogenic FIB-SEM studies. Reach out to our specialists to learn which configuration would best support your research.