silicon design

Throughout the current millennium, System-on-Chip (SoC) has been the gold standard for optimizing performance and cost of complete electronic systems. By incorporating practically all the phone’s digital plus analog capabilities onto a single, giant chip, the mobile phone processor serves as a near-perfect exemplar of SoC. But today’s leading integrated circuits (IC) are pushing up against the upper limit of a chip’s size which is limited by the manufacturing equipment’s optical reticle size. This has proven difficult to increase and has grown only slowly over the years. Yet market pressure continues unabated for bigger, more capable electronic systems with more integrated memory, more digital logic, and more analog/mixed signal circuitry. An emerging solution to this tension is 3D and 2.5D multi-die chip assemblies – often referred to as 3D-IC. The key technology breakthrough of 3D-IC is that it makes it possible to spread a system out over multiple, smaller chips that are then assembled close together and interconnected with high-speed, low-power interconnect technologies. By abandoning the need to integrate an entire system on a single SoC and instead allowing it to be disaggregated over multiple chips, 3D-IC enables Moore’s Law to break through the reticle size barrier, improves yield by shrinking the size of individual chips, and makes it possible to mix different process technologies optimized for each function. The Four Engines Driving Semiconductor Design The road forward is not without its challenges, however, and we are seeing design companies making significant efforts to adapt and come to grips with the following four technology and market drivers: The requirement for concurrent multiphysics analysis to ensure reliable and efficient electronic systems The blurring of the lines between silicon and system The need for open and inclusive multiphysics platforms that interoperate with the multitude of design platforms The need for, and value of, bespoke silicon for hyperscalers and system companies Blurring of Silicon and System Design The advent of 3D-IC opens up new horizons for solutions that can be implemented in silicon. But it also forces a closer integration between two distinct technology markets that have co-existed symbiotically for many decades: IC design and printed circuit board (PCB) design. These markets use different tools, different data formats, different manufacturing back-ends, operate at different computational and geometric scales, and focus on different physical concerns. Yet, 3D-ICs share many aspects of both markets: They include monolithic chips but also board-like substrates to stitch the chips together. And in between the two disciplines is packaging, a completely different domain that is requiring companies to re-imagine their design capabilities and flows, as well as their organizational structure. Open, Extensible Multiphysics Platforms The siloed isolation of chip design from PCB design and package design means that each of these markets has developed insular data structures that are ill-suited to deal with the breadth of multiphysics analysis for 3D-IC design. Many different physical disciplines, including computational fluid dynamics, mechanical stress, and electromagnetic radiation, all need to work together based on open and extensible multiphysics platforms. These platforms must embrace the modern cloud compute paradigm and enable an ecosystem by allowing individual design platforms to connect for comprehensive multiphysics analysis. Bespoke Chips Today’s market-leading companies are heavily dependent on technology for their continued success and market differentiation. Everybody from online retailers to telecommunications to social networking companies and hyperscalers are moving away from off-the-shelf solutions and turning to custom-built silicon to give them an edge. Many of these companies are seeking to gain market share by leveraging proprietary AI/ML algorithms trained on their extensive troves of market data – but this requires huge amounts of compute power and specialized chips. Access to high-quality silicon solutions is vital in today’s world and the demand is for continually more complex and powerful electronics. 3D-IC an Inflection Point in Electronic Design To be sure, 3D-IC design is at an inflection point in electronic design and presents major challenges that are realigning the electronic design industry around this new reality. For more insights on this topic from a semiconductor industry leader, please view the Keynote Address 2.5D and 3D – The Road Ahead by Vicki Mitchell, VP Engineering, Arm Central Engineering Systems Group presented at the latest Ansys IDEAS Forum. And for an EDA perspective, please view Successful 2.5D and 3D Multi-die Silicon System Design Using Synopsys’ 3DIC Compiler and Ansys’ Multiphysics Analysis from Synopsys SNUG World 2021. About John Lee John Lee is general manager and vice president of the Ansys Electronics and Semiconductor Business Unit. Lee co-founded and served as CEO of Gear Design Solutions (now Ansys), developer of the first purpose-built big data platform for integrated circuit design. He cofounded two other startups (Mojave Design and Performance Signal Integrity), which successfully exited into companies now part of Synopsys. He holds undergraduate and graduate degrees from Carnegie Mellon University.

Spend any time with Ansys’ John Lee, Rich Goldman or Marc Swinnen and you’ll hear plenty of optimism about the semiconductor industry even though they tick off a long list of looming design challenges. The need for reliable and effective electronic systems, they emphasize, is great and runs through high tech, aerospace and defense, automotive, IoT and 5G with communications being a common denominator. The three are especially bullish these days on changing market dynamics brought on by systems companies building company-specific bespoke, or custom, silicon. These systems companies are building chips with a different perspective and a fresh look at silicon design, a move away from the more traditional segment-specific silicon due to much more complexity. Ansys, a member of the ESD Alliance, a SEMI Technology Community, is a 4,100-employee company with a comprehensive portfolio of multiphysics engineering simulation software for product design, testing and operation products and services. John, Rich, Marc and I focused on Ansys’ semiconductor and electronics segment for our conversation. Smith: When did you notice the move by systems companies to build their own chips? What drives this trend? Lee: The inflection point was about three years ago when hyperscale data center and system companies recognized they needed an enterprise system design platform. They are designing bespoke silicon, driven to do this for cost efficiencies and to avoid relying on outside suppliers. They also want differentiation based on their specific platform needs so they can optimize compute power to their specific needs. Smith: What is driving the trend for multiphysics experience to ensure effective and reliable electronic systems? Lee: The increasing need for multiphysics analysis is acute. The physics of 3D IC, for example, brings in mechanical engineering with the convergence of mechanical and electrical as 3D emerges at the intersection of IC and System. As a result, physics becomes a necessity to analyze the stability of the chip in the package. Goldman: As well, the move to stacked chips, 3D IC and wafer-on-wafer requires thermal, electromagnetic and mechanical analysis in addition to the traditional analysis for function, performance and power. They all need to be analyzed together, not serially. It becomes multiphysics, not multiple physics. Smith: Two distinctly different disciplines – multiple physics and multiphysics – are needed for semiconductor design. How are they different? Why the need now? Swinnen: Multiple physics refers to the sheer breadth of physics that is now needed to analyze from the IC up to the largest system whereas multiphysics refers to the capability to analyze several physical effects concurrently, accounting for their impact on the design and interactions between various physics. Multiphysics are necessary to analyze the full context of the system environment – from nanometers to kilometers – for multi-chip packaging, chip-to-package-to-silicon and systems with multi-domain guidance. Goldman: A self-driving car, as an illustration, includes AI systems-on-chip, solid-state sensors, infotainment systems and radar/lidar detectors that must all work in the rain, the heat and the bitter cold. Smith: Why are design groups being reorganized to include expertise in mechanical and electromagnetic issues? Swinnen: Complexity has exploded, driven by a long list of technical requirements and, perhaps, mischaracterization. Goldman: Just consider the system on chip, mischaracterized by the semiconductor industry. The chip is never a system by itself. Rather, it is a complex component in a larger system and must be analyzed in that context. 3D IC is where this comes together and forces a recognition of physics outside the traditional scope of SoC design. 3D IC chips are much closer together on the board and it takes multiphysics embedded into the workflow of semiconductor design, packaging, system design and 3D IC to ensure they work reliably and efficiently. Smith: What is the solution? Goldman: It’s clear a specialized digital thread is necessary to move disparate groups with expertise in systems, physics and silicon together. Today, these groups or disciplines might not exist in the same company, whether it be a foundry, fabless or outsourced semiconductor assembly and test (OSAT) company. Lee: In order to unify the entire system design environment, a cloud-based, open and extensible heterogenous enterprise compute platform is required. It is similar to the SaaS-based business model and known as Simulation-as-a-Service (also SaaS). While vertical integration of design groups is already taking place at leading system design houses, there have also been advances in electronic design tools. These are starting to offer more comprehensive multiphysics capabilities including thermal, fluid dynamics (CFD), mechanical stress and reliability analysis in a single analysis cockpit. Today’s system designers face two platform challenges: First, they need an environment that is open enough to accept analysis results from multiple sources so that they can be overlapped and cross-analyzed. Second, the design platform must have the capacity to handle the enormous amounts of data generated by the latest 3-nanometer chips and 3D IC systems, and this implies an intimate coupling to elastic cloud computing. The days of an engineer writing Perl scripts and handing it off to someone else are gone. We believe that the industry is responding to this challenge with a new generation of design platforms that a cloud-native, open and extensible to allow heterogenous enterprise design. We are definitely at an inflection point in electronic design today, but the electronic industry has faced these before an we are confident it will master these challenges as well. About Rich Goldman Rich Goldman is director of marketing for the Electronics and Semiconductor Business Unit of Ansys. He holds a Bachelor of Science degree from Syracuse University and an MBA and Master of Science degree in Engineering Management. Moscow Institute of Electronic Technology (MIET)’s first honorary professor, he is also the recipient of honorary PhD degrees from Russian-Armenian (Slavnoic) University and State Engineering University of Armenia for contributions to the advancement of Armenia’s high-tech education and economic ecosystem. Rich served on EDAC’s board of directors. About John Lee John Lee is general manager and vice president of the Ansys Electronics and Semiconductor Business Unit. Lee co-founded and served as CEO of Gear Design Solutions (now Ansys), developer of the first purpose-built big data platform for integrated circuit design. He cofounded two other startups (Mojave Design and Performance Signal Integrity), which successfully exited into companies now part of Synopsys. He holds undergraduate and graduate degrees from Carnegie Mellon University. About Marc Swinnen Marc Swinnen is director of product marketing for the Electronics and Semiconductor Division of Ansys. He holds Master degrees in Electronic Engineering and Industrial Management from KU Leuven, Belgium, as well as an MBA from San Jose State University. About Bob Smith Robert (Bob) Smith is executive director of the ESD Alliance, a SEMI Technology Community. He is responsible for the management and operations of the ESD Alliance, an international association of companies providing goods and services throughout the semiconductor design ecosystem.