Finding the right semiconductor failure analysis lab often depends less on the laboratory’s name and more on whether it has the equipment and technical expertise required for your specific failure. A package delamination problem may require Scanning Acoustic Microscopy. A suspected interconnect defect may require FIB cross-sectioning and SEM inspection. Leakage inside an IC may require EMMI or OBIRCH, while a nanoscale transistor defect may ultimately require nanoprobing and TEM. For this reason, semiconductor engineers often search for a failure analysis laboratory by technique or equipment.
This guide provides a practical overview of the main semiconductor failure analysis techniques and the types of problems each one is commonly used to investigate.
| Equipment / Technique | Common Applications | Typical Failures Investigated |
|---|---|---|
| FIB / FIB-SEM | Site-specific cross-sectioning, circuit edit, TEM preparation | Vias, contacts, interconnect defects, buried structures |
| SEM / SEM-EDS | High-resolution imaging and elemental analysis | Cracks, particles, corrosion, metal defects, contamination |
| TEM | Nanoscale structural and materials analysis | Transistor defects, interfaces, crystal defects, advanced-node failures |
| X-Ray / 3D CT | Non-destructive internal package inspection | BGA defects, solder joints, bond wires, die attach, microbumps |
| C-SAM / SAM | Acoustic inspection of package interfaces | Delamination, cracks, voids, die-attach defects |
| EMMI / Photon Emission | Electrical fault localization | Leakage, junction defects, latch-up, transistor failures |
| OBIRCH | Laser-based resistance-change localization | Resistive shorts, leakage paths, interconnect defects |
| Thermal Imaging / Lock-In Thermography | Hot-spot localization | Shorts, leakage, localized power dissipation |
| Nanoprobing | Transistor and interconnect electrical characterization | Individual transistor failures, contacts, local electrical defects |
| Decapsulation | Exposing the semiconductor die for further analysis | Preparation for EMMI, probing, optical and physical analysis |
| Cross-Sectioning | Internal structural examination | Package defects, solder joints, vias, material interfaces |
| EDS / EDX | Elemental identification and material characterization | Contamination, corrosion, foreign particles, process residues |
Focused Ion Beam (FIB) is one of the most important tools used in advanced semiconductor failure analysis.
A FIB can precisely remove material from a selected region of an IC, allowing buried structures to be exposed without cross-sectioning a large area of the device.
Common applications include:
A combined FIB-SEM system allows material to be removed with the ion beam while the newly exposed structure is inspected with an electron microscope.
If electrical fault localization has already identified a very small Region of Interest, a lab with FIB capability is often the logical next step.
Scanning Electron Microscopy (SEM) provides high-resolution images of exposed semiconductor and package structures.
SEM is commonly used to investigate:
When SEM is combined with Energy Dispersive X-ray Spectroscopy (EDS/EDX), the lab can also obtain elemental information from suspicious material. For example, if SEM reveals a particle bridging two conductors, EDS may help determine whether the particle contains elements associated with metal, process residue or environmental contamination.
Transmission Electron Microscopy (TEM) is used when extremely high-resolution structural analysis is required. TEM is particularly valuable for examining very small semiconductor structures and material interfaces.
Typical applications include:
TEM normally requires an extremely thin sample from the exact failure location. For this reason, TEM failure analysis is frequently combined with FIB sample preparation.
X-ray inspection is one of the most useful non-destructive techniques for semiconductor package analysis. It allows the lab to inspect structures hidden inside a package before the device is physically opened.
Typical applications include:
Simple structures may be analyzed using 2D X-ray, while more complex packages may require 3D X-ray computed tomography (CT). 3D CT is particularly valuable when multiple structures overlap in a conventional X-ray projection.
Scanning Acoustic Microscopy (SAM) uses acoustic waves to identify changes at interfaces inside semiconductor packages. It is especially sensitive to small gaps and interface separation.
SAM is commonly used to detect:
C-SAM is particularly useful when the suspected failure involves an interface between two materials rather than a metallic structure. This makes SAM and X-ray highly complementary. X-ray is particularly useful for internal geometry, metals and solder. SAM is particularly useful for delamination, gaps and interfaces.
Emission Microscopy, often referred to as EMMI, is used to locate electrically active defects within semiconductor devices. Under electrical bias or operation, certain abnormal regions can emit very small amounts of light.
Sensitive imaging systems can detect these emission sites and correlate them with the IC layout. Typical applications include localization of:
The advantage is that the technique can help identify a small suspicious region before physical analysis begins. Once the emission site has been localized, techniques such as FIB, SEM or TEM may be used to investigate the physical defect.
OBIRCH — Optical Beam Induced Resistance Change — is a laser-based fault-localization technique. A laser scans across the IC while changes in the electrical behavior of the device are monitored.
Localized heating caused by the laser can alter the resistance of a defective region. This makes OBIRCH useful for locating:
OBIRCH is especially useful when the electrical failure exists but there is no obvious visible physical defect. After localization, targeted physical analysis can be performed.
Electrical shorts and leakage frequently generate heat. Thermal imaging can therefore be used to identify hot spots associated with abnormal power dissipation. Lock-in techniques improve sensitivity by synchronizing electrical stimulation of the failure with thermal measurement.
Typical applications include:
Thermal fault localization can sometimes narrow a problem from an entire package or circuit board to a very small Region of Interest before destructive analysis begins.
Semiconductor nanoprobing allows electrical measurements to be performed directly on extremely small semiconductor structures. Nanoprobes can be positioned on:
The technique can be used to characterize individual transistors and compare failing structures with known-good devices. Nanoprobing is particularly useful when fault localization has narrowed the failure to a small group of transistors but additional electrical characterization is required before physical analysis.
It is frequently combined with:
Sometimes the first challenge is simply gaining access to the semiconductor die. IC decapsulation removes package material while attempting to preserve important structures such as:
Decapsulation methods may include:
The appropriate technique depends on the package, materials and analysis that will follow. If the device must remain electrically functional after opening, this requirement should be discussed with the laboratory before decapsulation begins.
Cross-sectioning is used to expose the internal structure of a semiconductor package or device.
Methods can include:
Mechanical cross-sectioning is useful for larger package structures such as solder joints and package interfaces. FIB is usually preferred when the Region of Interest is very small and must be targeted precisely.
The location of the defect should ideally be established before destructive cross-sectioning begins.
You do not always need to know the exact technique before contacting a semiconductor failure analysis lab.
A useful starting point is the failure signature.
Look for:
C-SAM / Scanning Acoustic Microscopy
Look for:
X-Ray / 3D CT
Consider:
EMMI, OBIRCH or thermal fault localization
Look for:
FIB + SEM
Look for:
SEM + EDS
Consider:
Nanoprobing followed by FIB/TEM if required
Look for:
FIB sample preparation + TEM
Look for:
IC decapsulation
Complex semiconductor failures are rarely solved by a single instrument.
For example:
Electrical leakage
↓
EMMI or OBIRCH localizes the defect
↓
FIB exposes the Region of Interest
↓
SEM examines the defect
↓
TEM provides final nanoscale characterization
Similarly, a package failure might follow:
Electrical open
↓
X-ray inspection
↓
C-SAM
↓
Targeted cross-section
↓
SEM inspection
The most important capability of a good failure analysis laboratory is therefore not simply owning equipment. It is knowing which technique to use, in which order, while preserving the evidence required for the next step.
AnySilicon helps semiconductor companies identify failure analysis providers according to the equipment, technique and device expertise required for the investigation.
You may be looking for a lab offering:
When submitting a requirement, provide the device type, package, electrical failure signature, suspected failure area and any analysis already completed.
The more accurately the failure is described, the easier it is to identify a laboratory with the appropriate equipment and semiconductor failure analysis expertise.
