Detectives in a Nanotech World
Freescale Product Analysis Labs provide the expertise and analytical capabilities necessary to help develop high performance and high quality new products and technologies. Additionally, the labs provide the primary forensic analysis for Freescale’s aggressive continuous improvement efforts and for analyzing customer reported issues.
Freescale Product Analysis teams are located throughout the world and have decades of product analysis experience. The rich expertise of
the lab staff combined with industry-standard techniques and internally developed tools enable product analysts to locate sub-micron defects
among hundreds of millions of transistors on a silicon IC. This formula is instrumental in providing an accurate understanding of a
failure’s root cause which enables rapid corrective action and prevents similar defects moving forward.
The Product Analysis flow employs the following six steps:
Step 1 - Reproducing the Failure
One of the first steps required to determine the root cause is to reproduce the IC's failure mode in a laboratory
environment. Product analysts use Evaluation Boards, Digital Testers and other tools for this critical step. Special care, such as
the use of ESD protection, is taken during this step and throughout the product analysis flow to help ensure that new defects are not
introduced during the analysis process.
Step 2 - Package Analysis
The IC package is carefully inspected to determine whether or not the physical defect is associated with the package
that surrounds the die. The product analyst can employ an array of package analysis tools and techniques, such as optical inspection,
scanning acoustic microscopy, or X-ray. If the defect is found to be located in the package, a package analyst will carefully isolate
and characterize it using techniques described below.
Step 3 - Defect Spatial Localization
If there is no defect in the package, the analysis moves on to the silicon IC itself.
The product analysts use advanced localization techniques to identify a subset of transistors that may explain the observed failure mode.
The device package is first carefully removed to expose the silicon die. Localization techniques are then employed to narrow down the area
within the die that may contain the defect causing the observed failure mode. The tools available for this step range from equipments
that can detect visible and infrared lights to software developed by Freescale for Product Analysis. The key commonality of the
localization tools and techniques is the ability to narrow down the area of interest in a non-destructive manner. Light emission
microscopy, thermal detection techniques, and diagnostic fault simulation are just a few of the techniques available to an analyst for
defect spatial localization.
Step 4 - Advanced Electrical Analysis
Once a small area within the IC has been identified, advanced analytical techniques are employed to pin-point
the individual transistor or component that may be causing the observed failure mode. Typically, a product analyst starts with
non-destructive techniques, such as microprobing, to further reduce the number of potentially defective components. Destructive techniques,
such as atomic force probing, might be used subsequently to identify the single component that is causing the observed failure mode and
to characterize the defective component electrically.
If the defective area has been isolated to the device package, then a package analyst probes between the package layers to further
pinpoint the component that is causing the observed failure mode. The analyst starts by probing the top two package layers. If a
defective signal is not detected, then the analyst removes the top layer that was just probed and proceeds to probe the next two package
layers. This iterative process is performed until a defective signal is found.
Step 5 - Physical Analysis
The goal of physical analysis is to identify the physical defect that correlates, without ambiguity, to the electrical
signature of the failing component. A variety of physical analysis techniques are available for this step. A common physical analysis
technique is to selectively remove each layer of the integrated circuit or package layer followed by inspection with an electron or optical
microscope. Cross-sectioning is another common technique typically employed when the defect is located between two layers. When physical
and spatial characteristics of the defect are not sufficient, material analysis can be used to gather more information. Energy Dispersive
Spectroscopy (EDS) and Transmission Electron Microscopy (TEM) are just a few examples of material analysis techniques available in Freescale
Product Analysis Labs.
Step 6 - Documenting the Analysis
The product analysts will use the results from both the electrical analysis and the physical analysis to arrive at a
coherent failure mechanism that explains the observed failure mode. Once the analysts reach a conclusion, the failure root cause along
with the analysis process steps are documented in a report. The report is then forwarded to the appropriate groups outside the product
analysis team, such as product engineering, manufacturing engineering, assembly, test engineering or design engineering, so that corrective
action can be rapidly implemented.
Freescale Product Analysis Labs play a critical role in the journey to zero defects. The Product Analysis teams use their
analysis experience, industry standard and internally developed tools and techniques to identify a physical defect that clearly explains the
observed failure mode in an integrated circuit or in the package that surrounds the IC device. The analysis steps, results and conclusion
are communicated to the appropriate groups within Freescale so that a solution that will eliminate the cause of the failure can be implemented
Freescale Product Analysis Labs also work closely with Research and Development teams to create the next generation of products that
meets customers’ needs and exceeds customers’ quality expectations. By identifying potential problems early in the product
development phase, these labs help accelerate the availability and quality of new products to all Freescale’s customers.