When Tower engineers discovered a discrepancy between Calibre xRC extraction and Raphael™ field solver results, Mentor engineers helped them quickly solve the problem, yielding Calibre xRC accuracy within 3% of field solver results.
“The Mentor support group is very professional and they handled all of my comments seriously. They kept me updated as solutions were found for my problem.”
Erez Sarig, Engineer, Tower Semiconductor
An Unexpected Condition
Tower tests their Calibre xRC runset results against the Raphael field solver and on multiple design flows and test chips to verify accuracy. When Tower engineers encountered an unusual situation in which the Calibre xRC extraction results did not match the Raphael data, they called on Mentor to help diagnose the problem.
Runsets are Calibre templates used by IC designers to easily access the correct design rule files, run directories, calibration factors and other required settings. For fabless companies, Calibre runsets are included in their design kit to help them create accurate extraction netlists and simplify the IC manufacturing process.
Mentor Provides Flow Engineering Support
After careful analysis, Mentor engineers determined that the discrepancy resulted from a difference in the assumptions Calibre and Raphael make about how to calculate drawn dimensions. The Calibre xRC default assumes drawn dimensions are calculated from the bottom point of trapezoidal-shaped metal line structures, while Tower was calculating their drawn dimensions at a higher position in the trapezoidal shape.
It was this simple difference that caused erroneous Calibre xRC parasitic extraction results. Mentor advised Tower engineers to use the Bias function in Calibre xRC to align the two tools. With appropriate adjustments Calibre xRC results were brought to within 3% of Raphael predictions and test chip measured values.
Conclusion: A Reliable and Accurate Extraction Flow
After completing thorough testing and validation, Tower engineers were confident that Calibre xRC provides a complete, reliable and accurate extraction flow, ensuring that Tower's customers can design and produce the highest quality integrated circuits.
Tower Semiconductor, Ltd.
Tower Semiconductor, Ltd. is an independent wafer foundry facility that provides specialized process technologies like non-volatile memory production, development of CMOS image sensors, and mixed-signal and RF solutions. In addition, they also supply technical manufacturing services and IC design support. ICs manufactured by Tower are used in diverse electronics applications, such as personal computers, photographic and office equipment, communications, automotive and medical products.