FIB Failure Analysis Services: Focused Ion Beam Drilling Into Root Causes

What Is FIB Failure Analysis?

Focused Ion Beam (FIB) failure analysis is a precision materials investigation technique that uses a focused beam of high-energy gallium ions to selectively mill, cut, and expose cross-sections of a material or device at specific, predetermined locations — with sub-micrometer positional accuracy. The FIB system then images the exposed cross-section using a scanning electron microscope (SEM) integrated within the same instrument (FIB-SEM dual-beam system), enabling simultaneous milling and imaging at the exact location of interest.

In electronic and materials failure analysis, FIB represents the culmination of the investigation. This precise surgical instrument reveals the physical defect at the location already pinpointed by electrical testing, emission microscopy, liquid crystal imaging, or acoustic microscopy. It is the technique that converts a failure mode identified at the device level into a specific, characterized physical defect at the atomic or near-atomic scale.

How FIB Works

Ion Beam Milling

A gallium liquid metal ion source (LMIS) generates a focused beam of Ga⁺ ions accelerated to 5–30 kV. The ion beam strikes the sample surface and sputters material through momentum transfer — removing material at precisely controlled rates. By scanning the beam over a defined rectangular region, a trench or cross-section is cut through the sample at any desired location. Ion beam current is varied — high current (several nA) for rapid bulk material removal, low current (tens of pA) for fine polishing and final cross-section surface preparation.

SEM Imaging

The dual-beam FIB-SEM has an SEM column mounted at approximately 52° to the FIB column. While the FIB mills the cross-section, the SEM simultaneously images the freshly exposed surface, providing real-time feedback on milling progress and revealing the sample’s cross-sectional microstructure as it is exposed.

Gas-Assisted Processes

The FIB system uses reactive gas injection to enable additional processes:

• Platinum or carbon deposition: A platinum or carbon precursor gas is decomposed by the ion beam to deposit a protective metallic or carbon cap over the area of interest before milling — protecting the fragile top surface from FIB-induced damage during cross-sectioning
• Gas-assisted etching: Reactive gases (XeF₂, Cl₂) enhance selective material removal — useful for silicon etching or encapsulant removal in semiconductor failure analysis

FIB Applications in Electronic Failure Analysis

Semiconductor Device Cross-Sectioning

The most common FIB FA application — cutting a precise cross-section through a specific transistor, contact, via, metal line, or bond pad identified as the failure site by prior localization techniques. The cross-section reveals:

• Gate oxide thickness and integrity
• Contact plug filling quality
• Metal interconnect void formation
• Electromigration-induced void and hillock formation
• Copper diffusion barrier integrity
• Solder bump composition and voiding

TEM Sample Preparation (TEM Lamella Preparation)

FIB is the dominant technique for preparing site-specific TEM (Transmission Electron Microscopy) samples from bulk materials. A thin lamella (~100 nm thick) is extracted from the exact failure site using FIB milling — the lamella is then transferred to a TEM grid for atomic-resolution imaging and EELS analysis. This site-specific TEM capability — previously impossible with traditional mechanical TEM preparation — transformed the field of failure analysis.

3D Tomography (FIB-SEM Serial Sectioning)

By alternating FIB milling of thin slices with SEM imaging of each exposed surface, a complete 3D reconstruction of the microstructure is produced through computational stacking of the 2D image slices. FIB-SEM 3D tomography reveals pore network connectivity, grain boundary morphology, precipitate distribution, and defect 3D geometry — providing information not available from any single 2D cross-section.

Passive Voltage Contrast (PVC)

When a cross-sectioned IC is imaged in SEM mode under FIB irradiation, conductor lines connected to ground appear dark while floating (disconnected) conductors appear bright — due to differential surface charging. PVC enables rapid identification of open circuits, broken vias, and missing contacts in IC metallization by their distinctive brightness contrast.

Microelectronics Circuit Edit

FIB can precisely cut metal interconnects (to break unintended connections) or deposit conductive metal lines (to create new connections) within an IC — enabling prototype circuit modifications and fault isolation verification without requiring new mask sets. While not strictly a failure analysis tool, circuit editing is a powerful complement to FIB FA.

FIB in Materials and Coatings Failure Analysis

Beyond semiconductor applications, FIB-SEM is widely used in:

Coating and Film Cross-Sectioning: Precise cross-sections through thin-film stacks (PVD/CVD coatings, paint systems, thermal barrier coatings) reveal layer thicknesses, interface quality, adhesion defects, and corrosion penetration with nanometer-level precision.

Corrosion Analysis: FIB sections through corrosion pits, stress-corrosion cracks, and intergranular corrosion reveal crack morphology, corrosion product chemistry, and the metal-corrosion product interface in 3D.

Additive Manufacturing Defect Analysis: Porosity, lack-of-fusion defects, and microstructural gradients in laser powder bed fusion (LPBF) parts are characterized by FIB-SEM cross-sectioning at specific locations identified by CT scanning.

Battery and Energy Materials: SEI layer thickness and chemistry, electrode particle fracture mechanisms, and lithium plating morphology in EV batteries are characterized at the nanoscale by FIB-SEM and site-specific TEM from FIB lamellae.

FIB Artifacts and Limitations

Gallium implantation: Ga ions from the beam implant into the near-surface region of the cross-section — potentially modifying the chemistry and crystal structure being analyzed. EDS/EELS analysis of FIB-prepared sections must account for gallium contamination.

Curtaining: Irregular milling rates across features of different hardness (e.g., soft polymer and hard metal in a bonded assembly) produce vertical striations (curtaining) on the cross-sectional surface, which are obscured by final low-current polishing passes.

Amorphization: The ion beam amorphizes a thin surface layer (~10–20 nm) of crystalline materials — requiring very low-current final polishing for EBSD or atomic-resolution TEM samples

Conclusion

FIB failure analysis — spanning precision cross-sectioning, TEM lamella preparation, 3D FIB-SEM tomography, passive voltage contrast, and circuit editing across semiconductor devices, thin film coatings, corrosion failures, additive manufacturing defects, and battery materials — provides the site-specific, nanoscale physical defect characterization that converts an electrically or optically localized failure into a confirmed root cause. Applying the right FIB technique at the right location — and accounting for artifacts such as gallium implantation and amorphization during interpretation — is what determines whether FIB analysis reveals the true defect rather than a preparation artifact, making precise failure localization before FIB cross-sectioning as critical as the FIB analysis itself.

Why Choose Infinita Lab for FIB Failure Analysis?

Infinita Lab is a trusted partner for Fortune 500 companies, offering FIB-SEM failure analysis and materials characterization as part of its vast catalog of testing services. We are a network of accredited testing laboratories across the United States equipped with state-of-the-art dual-beam FIB-SEM systems, operated by a team of top-tier specialists in semiconductor and materials failure analysis.

Looking for a trusted partner to achieve your research goals? Schedule a meeting with us, send us a request, or call us at (888) 878-3090 to learn more about our services and how we can support you. Request a Quote.

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