Current complexities involving the design and manufacturing of semiconductor manufacturing are parsed with the need to contract third-party foundry porting services, whose primary responsibility is to facilitate the transition of integrated circuits designed for one particular manufacturing process technology node to another manufacturing process technology node. That is why, as a young and rapidly developing area of engineering, VLSI design in USA, requires effective and low-risk foundry porting. This article aims at analysing the different aspects of the foundry porting service, with specific emphasis on the risks imposed by the service and the measures taken to overcome them.
The Importance of Foundry Porting in VLSI Design
VLSI (Very Large Scale Integration) is the backbone of most electronics systems that are in used today ranging from mobile phones to high-end computing systems. In line with technology nodes and file changing processes, designers are forced to migrate their initial designs to new foundries and process nodes. This process, known as foundry porting, is critical for several reasons:
Cost optimization: Increasing process complexity through moving to a new node can cut the manufacturing costs and ultimately increase yield rates.
Performance enhancement: Technological advances in new processes help in improving performance and power.
Supply chain diversification: Whereas, the risks associated with its supply chain can be managed through the option for designing for multiple foundries.
Product lifecycle management: Porting also enables the manufacturer to take advantage of new technologies and sustain the successful products for some more years.
However, foundry porting while beneficial has its pitfalls and could be detrimental to the organization involved. Semiconductor hardware design teams particularly the VLSI design engineering teams that are involved in hardware development services must be able to factor technical, logistical and economic forces to determine successful porting results.
Challenges in Foundry Porting
Process Differences: Every one of these foundries has essentially different PDKs, design rules, and manufacturing particularities. Translating design to these differences is not easy and it takes a lot of time to run out the best design.
Performance Variations: By moving to a new process, the telecommunication engineers might experience certain changes in the circuit characteristics, power, or area.
Intellectual Property (IP) Compatibility: The IP blocks may not be available, or at least tuned for the target foundry, and may take a great deal of alteration or even redesign.
Tool Chain Compatibility: There might be a need to redesign the design tools and the design flows in order to accommodate of the new foundry.
Timing Closure: Getting the timing closure in the new process might turn out to be difficult if not impossible because parasitic effects are different and the devices themselves are different.
Cost and Time Overruns: Failure to understand these complexities can result to poor porting done with a lot of delay or even too much expenses.
A Comprehensive Risk Mitigation Strategy
Early Planning and Assessment
Analyse the design and the target foundry before proceeding with the actual porting process itself. This includes:
- Assessing the extent of IP consonance with the target process
- Considering the robustness of the design process to process variations
- Critical path analysis and areas of prospective congestion
- Resource acquisition and time scheduling
Robust Design Practices
Implement design practices that enhance portability from the outset:
- Wherever possible, choose parameterized cells and modules for your project.
- Limit special foundry or product attributes
- Using the concept of hierarchical design for easier partitioning and hence porting.
- Include all the design for testability (DFT) measures
Comprehensive Characterization and Modelling
Develop accurate models and characterization data for the target process:
- Do as many SPICE simulations as possible to investigate the device responsiveness
- Develop detailed timing and power models for key block
- Establish precise parasitic extraction models
Iterative Verification and Validation
Implement a rigorous verification and validation process throughout the porting effort:
- Emphasize on evaluation and analysis of designs
- Conduct first and second level of regression testing at each level of porting process
- Use formal methods like formal verification and emulation for further verification.
Collaboration with Foundry Partners
Establish strong partnerships with foundry providers:
- Communicative with foundry technical teams as early and as often as possible
- Utilize Design enablement services offered by the foundry
- Take pre-release versions of new process technologies.
Tool Chain Optimization
Ensure that the EDA tool chain is optimized for the target foundry:
- It is necessary to update or replace the tools used in order to facilitate the new process.
- Assess the level of accuracy and effectiveness of the tool on useful realistic samples
- Write special scripts and tools that can help to make the process of porting easier.
Knowledge Management and Training
Invest in knowledge management and team training:
- Writing down the how’s and what’s of porting from previous porting projects
- Aim at offering specific training on new flow process and design approaches.
- Promote Organizational Learning and Development
Risk Management and Contingency Planning
Develop a comprehensive risk management strategy:
- Cross check of risk factors and their effects on the projects.
- Formulate risk management plan for risks that are deemed to be risky
- There should be sustainable countermeasures for failure elements that are most sensitive.
Incremental Porting Approach
Consider an incremental approach to porting, especially for complex designs:
- Critical blocks or subsystems should be delivered to the port firstly
- Ensure that performance and functionality factors are checked at since they are critical path works.
- Examine early outcomes and first reviews and fine-tune the used approach.
Post-Porting Optimization
After initial porting, focus on optimizing the design for the new process:
- Optimize or further adjust the timing and power specifications
- Find out more about additional features of the new process to make it perform even better.
- Undergo rigorous simulations and analysis only after the design has been physically implemented on the layout.
Conclusion
Foundry porting services are one of the necessary components maintained in the VLSI designing engineering services, particularly in leading countries like the USA. While creating complex reference designs of actual silicon, efficient design ‘migration!’ between various foundries and process nodes becomes paramount for the hardware development services.
A risk management perspective is provided below that outlines how VLSI design teams can approach the issues of foundry porting in a more integrated way to improve success. It includes early planning, sound design procedures, co-operation with the foundry and constant improvement, which also lead to optimal solutions in the sense of performance, costs and time to market.
