integrated circuits

Leading experts gathered at the Power and Opto Semiconductor Forum at SEMICON Taiwan 2022 last year to discuss the growing importance of the devices in semiconductor innovation as the chip industry works to develop a robust compound semiconductor ecosystem.

With the emergence of consolidation as a potent engine of semiconductor industry growth, global mergers and acquisitions are sweeping the industry as companies look to accelerate advances across segments including data centers, AI, IoT and automotive chips.

SEMI spoke with Christian Driller, Vice President of Research and Development at Comet Yxlon, about opportunities to accelerate time-to-market and increase yield for advanced packaging manufacturers through x-ray inspection.

Electronics industry experts will offer insights into key aspects of the radio frequency (RF) challenge – from materials and devices to ICs and modules – at ITF Beyond 5G at SEMICON Europa 2022, Nov. 15-18 in Munich, Germany.

Atomic Layer Deposition (ALD) players are poised to seize a new growth opportunity after the chip shortage pushed manufacturers to announce fab capacity expansions worldwide. Driven by the wafer production volume increase, ALD solutions are now expected to grow and enter the MtM devices market.

Anna Fontanelli, Monozukuri’s founder and CEO, is an expert in deep-submicron silicon technology and design tools shares her view on the state of Moore’s Law and challenges surrounding 2.5D integration, 3D chip stacking & advanced packaging, as well as the chip design industry’s startup environment.

China’s semiconductor sector has exploded to become one of the largest in the world and match the region’s prominence as the biggest consumer of chips. From 2015 to 2020 alone, revenue of China’s integrated circuit (IC) industry expanded at a rapid clip of 20% CAGR (RMB) to $128 billion.

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.

After logging record shipments in the first quarter of 2021, the silicon wafer industry may need to start greenfield projects as soon as this year to boost capacity over the next two years as market demand and average selling prices continue to improve.

A change is underway in the manufacturing sector as the use of curvilinear shapes on photomasks grows, leading to the real possibility of curvilinear shapes in designs. It may just be the start of a revolution away from Manhattan or rectangular shapes to curvilinear shapes. Changing the physical design infrastructure to be curvilinear seems too daunting a task. Are curvilinear shapes in designs a real possibility? I turned to Aki Fujimura, CEO of D2S, a member of the ESD Alliance, a SEMI Technology Community, to further explain the shape of the future. Smith: What is the difference between Manhattan and curvilinear shapes? Fujimura: Manufactured masks and wafers are all curvilinear, even if the input CAD geometries are rectilinear (shown in Figure 1). It’s always been true that nature can’t make 90-degree turns, so sharp corners were always a matter of how closely you looked. These days, at the leading-edge nodes and their required resolutions, wafers and even masks are all visibly curvilinear as you can see in the graphic on the left in Figure 2. Since the 1980s, both chip design and chip manufacturing systems have used axis-aligned rectangles, or “Manhattan” geometries, because 1) that was sufficient to design transistors and interconnect for the most part, and 2) CPU-based computer algorithms can be made much more efficient for Manhattan geometries. Curvilinear shapes can be piecewise linear polygons of some resolution, or spline-like formats that are curvilinear at any resolution, or specific curved patterns like circles and ovals. Figure 1: All shapes on masks and wafers are curvilinear, even if the input geometries are Manhattan. Source: D2S Smith: What are the benefits of curvilinear masks? Fujimura: The manufacturing side of the semiconductor community knows that the best possible process window for wafer lithography is obtained by using curvilinear correction of mask shapes instead of Manhattan shapes. There have been numerous studies on the topic over several decades. The technique to generate purely curvilinear mask shapes is known as inverse lithography technology or ILT and is an advanced form of optical proximity correction (OPC). At a February 2020 eBeam Initiative event, Micron Technology presented a study showing process window improvement up to 85% for advanced memory designs as a result of using curvilinear ILT (shown in Figure 2). Additionally, Ryan Pearman from D2S presented a study at Photomask Japan 2019 showing that it is preferable to move toward a completely curvilinear paradigm, not only because ILT is better, but because the mask manufactured will have reduced variability. Figure 2: Micron Technology explained the benefits of curvilinear mask shapes for advanced memory at the eBeam Initiative event during 2020 SPIE Advanced Lithography Conference. Source: Micron Technology Smith: If the benefits have been known for decades, why is it happening only now? Fujimura: Several things happened at the same time. Multi-beam mask writing is now available. GPU acceleration for general computing has become mainstream. And wafer process window (resilience to manufacturing variation) is increasingly a problem for the leading-edge nodes as we are in the 5nm node, going to 3nm. Curvilinear ILT is needed much more now than before, will soon be needed for EUV lithography too, and is now possible because of multi-beam mask writing and GPU acceleration. Smith: Curvilinear mask shapes enable curvilinear design shapes too? Fujimura: Adoption of curvilinear mask shapes is the first step in targeting curvilinear shapes on wafers. Without curvilinear masks, it is difficult to target and reliably manufacture curvilinear designs. Curvilinear ILT works in the pixel-space to output the desired mask shape to maximize the process window for wafer lithography. A side effect of curvilinear ILT is that it can also take curvilinear targets as input. ILT, most likely GPU-accelerated ILT, works with rasterized input data, so the ILT algorithm itself is not affected even in runtime by having any amount of curvilinear design data. The resulting mask shapes are written in multi-beam mask writers, which write pixels with doses. They too will write curvilinear masks at the same speed as Manhattan masks. Suddenly now, curvilinear designs can be handled by chip manufacturing equally well for the first time in about 30 years. Smith: But curvilinear designs would be hard, right? There are a lot of tools that depend on the Manhattan assumption. Fujimura: Yes, you’re right. We’re not going to suddenly see chips that have curvilinear routing all over the place, or curvilinear intra-connect in standard cells or memory cells. The entire physical design infrastructure that includes place and route, timing, custom layout, parasitic extraction and design rule checking moving to curvilinear design all at once is extremely unlikely. Could portions of these problems be tackled for specific cases over time as “hot spot” solutions? With GPU-accelerated SPICE being available now, as an example, if GPU acceleration is adopted for design, the same transformation that happened in manufacturing can (gradually) happen in design too. The key question is whether it’s worth the trouble. Smith: Is it worth the trouble? Fujimura: I don’t know if it’s worth the trouble for the entire infrastructure. For hot spots, “hot” for various reasons, there are certainly benefits. Jogging a 32-bit bus by one grid is certainly much more economical space-wise with curvilinear shapes. Inside standard cells or memory cells, there are certain types of features that pack better with curvilinear designs. In general, interconnect is the limiter to chip size of course, but there are always critical areas that could use help to shrink. There are manufacturability benefits as well. In general, when something changes so drastically as this for the first time in 30 years, there’s bound to be some innovation that takes advantage of the discontinuity. Let’s see what the combined capitalistic power of the entire community might be able to come up with. The first thing is to let everyone know that curvilinear designs will be manufacturable today. Hear insights from other leading electronic system design industry CEOs at the SEMI ESD Alliance CEO Outlook on May 18, 2021, 2:00pm-3:00pm PDT. Panelists will discuss the state of the industry along with their views of the outlook for the coming years. Registration is free for SEMI members. 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.