August 16, 2007 – Just weeks after acquiring lithography modeling and pattern-synthesis developer Invarium, Cadence Design Systems is making another splash across the DFM and litho marketspace with its purchase of Clear Shape Technologies. Terms of the deal, which closed Aug. 15, were not disclosed.
Clear Shape’s technology — which many in the industry point to as the best example of an actual design-side DFM tool — improves the ability to detect lithographic ‘hot spots,’ as well as model the impact of optical processing variations on the electrical performance of the chip, the companies explained. The meat of the acquisition will be integrating Clear Shape’s predictive (and manufacturing/OPC/tool independent) lithography capabilities into the Cadence DFM environment, noted Atul Sharan, president/CEO of Clear Shape, in a statement.
“We’ve always believed that the combination of rule-based and model-based technologies is the future of DFM, and Cadence shares this belief,” he said. “This synergy allows us to provide the industry leading support for the widest range of advanced IC designs.”
Tackling lithographic effects early in the design phase is an increasingly important factor in getting 65nm and below chip designs ramped to production, noted Richard Brashears, corporate VP of manufacturing, modeling and implementation at Cadence.
InShape uses a nonlinear optical transformation algorithm to detect potential manufacturing failures during physical design to predict full-chip contour shape predictions across the process window (see figure). Using output from InShape, OutPerform takes timing, and place/route data together with encrypted fab technology files to identify timing and leakage parametric hotspots for violations due to systematic variations. The resulting timing optimization directive drives place/route tools.
Clear Shape has been working with TSMC, UMC, IBM, Samsung, Chartered, NEC, and others to correlate its contour predictions to a specific fab’s silicon (i.e., calibrating the models), and has achieved contour prediction calibration and hot spot detection for several customers, including TSMC (65-55-45nm), the IBM/Chartered/Samsung alliance (65nm), and NEC (90-65nm). STARC also is a recent customer.