Jointly developed with leading EDA providers, the process flows address AMS challenges from specification to verification

At next week's 50^th Design Automation Conference (DAC) in Austin, Texas, GLOBALFOUNDRIES will unveil a comprehensive set of certified design flows to support its most advanced manufacturing processes.

The flows, jointly developed with leading EDA providers, offer robust support for implementing designs in the company's 20nm low power process and its 14nm-XM FinFET process.

Working closely with Cadence Design Systems, Mentor Graphics and Synopsys, GLOBALFOUNDRIES has developed the flows to address the most pressing design challenges, including support for analogue/mixed signal (AMS) design, and advanced digital designs, both with demonstration of the impact of double patterning on the flow.

The GLOBALFOUNDRIES design flows work with its process design kits (PDKs) to provide real examples that demonstrate the entire flow. The user can download the design database, the PDK, detailed documentation and multi-vendor scripts to learn how to set up and use the GLOBALFOUNDRIES design flow. The flows use open source examples and provide the customer with working, executable and customisable flows.

"As the developer of the industry's first modular 14nm FinFET technology and one of the leaders at 20nm, we understand that enabling designs at these advanced process nodes requires innovative methodologies to address unprecedented challenges," says Andy Brotman, vice president of design infrastructure at GLOBALFOUNDRIES.

"By working with a new level of collaboration with EDA partners, we can provide enhanced insight into our manufacturing processes in order to fully leverage the capabilities of 20nm and 14nm manufacturing. This provides our mutual customers with the most efficient, productive and risk-reduced approach to achieving working silicon," adds Brotman.

Production Ready AMS flow from specification to verification

To address the unique requirements of analogue/mixed signal (AMS) design at advanced processes, GLOBALFOUNDRIES has enhanced its design flows to provide production quality scripts and packaged methodologies. The new reference flow establishes a working flow from specification to physical verification that has been taped out to be verified on working silicon.

The AMS reference flow provides comprehensive double pattern design guidelines. It gives overview of decomposition flow for both block level and chip level. The flow also addresses decomposition for different design styles. Recommendations for colour balancing, hierarchical decomposition, ECO changes are discussed. The flows also present decomposition impact on DRC run time and resulted database size.

Notably, the reference flow includes support for efficiency and productivity improvements in the Cadence Virtuoso® environment specifically for designing in a double patterned process. The flow includes support for Virtuoso Advanced Node 12.1 and provides efficient access to the tool's productivity benefits for physical design with real-time, colour-aware layout.

Circuit designers can assign "same net" constraints in the schematic, and the layout designers can meet these requirements as they create the physical view. Additionally, layout designers can take advantage of Virtuoso tool support for local interconnect, and advanced layout dependent effect management.

The flow also features interoperability with Mentor's Calibre nmDRC, nmLVS, and extraction products which address multi-patterning requirements for both double and triple patterning. In addition special settings for analogue design; auto-stitching and when to use it; and fill and colour balancing are described in detail.

The AMS flow provides detailed information on parasitic extraction and layout dependent effects, both of which introduce new challenges at 20nm and 14nm. For parasitic extraction, the flows are described in detail and customizable scripts and examples demonstrate OA and DSPF back annotation.

In addition the flows illustrate methodologies to predict layout-dependent effects during schematic design and methods to include full models in post layout extraction. PEX flows for Synopsys StarRC extraction, Cadence QRC and Mentor CalibrexRC are supported.

These flows serve as references to validate the correctness of the accompanying PDK as well as the vendor tools setup.

Sign-off ready RTL2GDSII flows that address double patterning

GLOBALFOUNDRIES is also making available new flows that support a complete RTL-to-GDSII design methodology for targeting its 20nm and 14nm manufacturing processes. The company worked with EDA vendors to certify the flows in their respective environments and provide a platform for optimized, technology-aware methodologies that take full advantage of the performance, power and area benefits of the processes.

The result is a set of fully executable flows containing all the scripts and template files required to develop an efficient methodology. The flows serve as a reference to validate the correctness of the accompanying PDK as well as the vendor tool setup.

What's more, the flows offer access to other critical and useful information, such as methodology tutorial papers; guidelines and methodologies for decomposition of double patterned layouts; PEX/STA methodology recommendations and scripts; and design guidelines and margin recommendations.

A critical aspect of manufacturing at this level is the use of double patterning, an increasingly necessary technique in the lithographic process at advanced nodes. Double patterning extends the ability to use current optical lithography systems and the GLOBALFOUNDRIES flows provide comprehensive double pattern design guidelines. They address design for double patterning and the added flow steps for different design styles and scenarios.

This includes support for odd cycle checking, a new type of DRC rule that must be met to allow for legal decomposition of the metals into two colours. This check is detailed in the flow and guidelines are provided to make sure it is met.

Synopsys and GLOBALFOUNDRIES worked together to minimize the impact of changes associated with the 3D nature of FinFET devices as compared to planar transistors. The two companies focused on making FinFET adoption transparent to the design team.

The collaboration on Synopsys' RTL to GDSII flow includes 3-D parasitic extraction with the Synopsys StarRC tool, SPICE modelling with the Synopsys HSPICE product, routing rules development with the Synopsys IC Compiler tool and static timing analysis with the Synopsys PrimeTime tool.