From Wafer Maps to Yield: Modus Uses Wafer Analytics to Unlock Yield Improvement

Modern semiconductor manufacturing generates enormous amounts of test data. When yield drops, engineers need more than isolated failure reports. They need a way to identify patterns across wafers, lots, and thousands of failing dies. This is where Cadence Modus Volume Diagnostics transforms failure analysis from a device-level activity into a comprehensive yield-learning solution.

During the fabrication of the chips, yield loss can occur due to defects, faults, or process variations. Yield is nothing but a percentage of non-faulty chips fabricated to the maximum number of ICs fabricated on the wafer.
Process variations, systematic defects, and manufacturing excursions often impact hundreds or even thousands of dies across multiple wafers. Traditional diagnostic approaches struggle to detect these broader trends efficiently.
Modus Volume Diagnostics is designed to analyze large populations of failing devices, enabling engineers to:

• Diagnosing failures in a distributed environment
• Track diagnostic progress through graphical user interface
• Store failure information and callout reports in a database
• Analyze trends across lots, wafers, and die locations
• Identify yield limiters faster

Wafer analysis in Modus involves the examination of multiple CPP (Chip Pad Pattern) data files to identify and diagnose manufacturing defects in VLSI wafers.

Preparing Failure Database

The volume diagnostics flow begins with collecting failure data from numerous devices. Each CPP (Chip Pad Pattern) file must include unique identifiers for the LOT and WAFER. Optionally, it includes conditions like temperature or voltage margins.

Automating Large-Scale Diagnostics

Modus automatically processes all CPP files in a specified directory and performs the complete volume diagnostic workflow. Engineers can launch diagnostics across hundreds of devices without manually analyzing each failure dataset.

Turning Failure Data into Actionable Trends

Once the diagnostic database is ready, Modus enables engineers to examine trends. The tool uploads diagnostic results into the volume database and automatically generates statistical summaries and categorization reports.
For example, trend reports can identify whether failures are concentrated in specific lots, and help distinguish between random defects and systematic manufacturing issues.

The training Diagnostics with Modus DFT Software v26.1 highlights lot-level categorization that quickly reveals the relative contribution of different lots to overall failure populations.

Analyzing Yield Problems with Wafer Maps

One of the most powerful capabilities of Modus Volume Diagnostics is its graphical wafer analysis interface.
The volume analysis GUI provides:

• Wafer maps
• Failing die summaries
• Categorization charts
• Diagnostic information dashboards

These visualizations allow engineers to quickly spot spatial defect patterns that may be invisible in text reports.

Conclusion

Wafer analysis in Modus is a comprehensive process that ensures the identification and diagnosis of manufacturing defects, leading to improved quality and yield in semiconductor manufacturing.

More About Diagnostics with Modus Training

The training, Diagnostics with Modus DFT Software v26.1, offers Cadence Modus Diagnostics capabilities to process hundreds to thousands of failing dies, correlate failure data with wafer locations, and use volume diagnostics to uncover yield limiters across lots, wafers, and die locations.

Choose the Cadence Training Menu that's right for you.

Happy learning!