JEDEC and the Open Compute Project rolled out a new set of guidelines for standardizing chiplet characterization details, such as thermal properties, physical and mechanical requirements, and behavior specs. Those details have been a sticking point for commercial chiplets, because without them it’s not possible to choose the best chiplet for a particular application or workload. The guidelines are a prerequisite for a multi-vendor chiplet marketplace.

AMD, Broadcom, Cisco, Google, HPE, Intel, Meta, and Microsoft proposed a new high-speed, low-latency interconnect specification, Ultra Accelerator Link (UALink), between accelerators and switches in AI computing pods. The 1.0 specification will enable the connection of up to 1,024 accelerators within a pod and allow for direct loads and stores between the memory attached to accelerators.

Arm debuted a range of new CPUs, including the Cortex-X925 for on-device generative AI, and the Cortex-A725 with improved efficiency for AI and mobile gaming. It also announced the Immortalis-G925 GPU for flagship smartphones, and the Mali-G725/625 GPUs for consumer devices. Additionally, Arm announced Compute Subsystems (CSS) for Client to provide foundational computing elements for AI smartphone and PC SoCs, and it introduced KleidiAI, a set of compute kernels for developers of AI frameworks. The Armv9-A architecture also added support for the Scalable Matrix Extension to accelerate AI workloads.

TSMC said its 2nm process is on target to begin mass production in 2025. Meanwhile, Samsung is expected to release its 1nm plan next month, targeting mass production for 2026 — a year ahead of schedule, reports Business Korea.

CHIPs for America and NATCAST released a 2024 roadmap for the U.S. National Semiconductor Technology Center (NSTC), identifying priorities for facilities, research, workforce development, and membership.

China is investing CNY 344 billion (~$47.5 billion) into the third phase of its National Integrated Circuit Industry Investment Fund, also known as the Big Fund, to support its semiconductor sector and supply chain, according to numerous reports.

Malaysia plans to invest $5.3 billion in seed capital and support for semiconductor manufacturing in an effort to attract more than $100 billion in foreign investments, reports Reuters. Prime Minister Anwar Ibrahim announced the effort to create at least 10 companies focused on IC design, advanced packaging, and equipment manufacturing.

imec demonstrated a die-to-wafer hybrid bonding flow for Cu-Cu and SiCN-SiCN at pitches down to 2µm at the IEEE’s ECTC conference. This breakthrough could enable die and wafer-level optical interconnects.

The chip industry is racing to develop glass for advanced packaging, setting the stage for one of the biggest shifts in chip materials in decades — and one that will introduce a broad new set of challenges that will take years to fully resolve.

Quick links to more news:

In-Depth
Global
Product News
Markets and Money
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Research and Training
Quantum
Events and Further Reading

In-Depth

Semiconductor Engineering published its Systems & Design newsletter featuring these top stories:

• RISC-V Heralds New Era Of Cooperation
• AI For Data Management
• Trouble Ahead For IC Verification

Global

STMicroelectronics is building a fully integrated SiC facility in Catania, Italy.  The high-volume 200mm facility is projected to cost over $5 billion.

Siliconware Precision Industries Co. Ltd.(SPIL) broke ground on an RM 6 billion (~$1.3 billion) advanced packaging and testing facility in Malaysia. Also, Google will invest $2 billion in Malaysia for its first data center, and a Google Cloud hub to meet growing demand for cloud services and AI literacy programs, reports AP.

In an SEC filing, Applied Materials received additional subpoenas from the U.S. Department of Commerce’s (DoC) Bureau of Industry and Security related to shipments of advanced semiconductor equipment to China. This comes on the heels of similar subpoenas issued last year.

A Chinese contractor working for SK hynix was arrested in South Korea and is being charged with funneling more than 3,000 copies of a paper on solving process failure issues to Huawei, reports South Korea’s Union News.

VSORA, CEA-Grenoble, and Valeo were awarded $7 million from the French government to build low-latency, low-power AI inference co-processors for autonomous driving and other applications.

In the U.S., the National Highway Traffic Safety Administration (NHTSA) is investigating unexpected driving behaviors of vehicles equipped with Waymo‘s 5th Generation automated driving system (ADS), with details of nine new incidents on top of the first 22.

Product News

ASE introduced powerSIP, a power delivery platform designed to reduce signal and transmission loss while addressing current density challenges.

Infineon announced a roadmap for energy-efficient power supply units based on Si, SiC, and GaN to address the energy needs of AI data centers, featuring new 8 kW and 12 kW PSUs, in addition to the 3 kW and 3.3 kW units available today. The company also released its CoolSiC MOSFET 400 V family, specially developed for use in the AC/DC stage of AI servers, complementing the PSU roadmap.

Fig. 1: Infineon’s 8kW PSU. Source: Infineon

Infineon also introduced two new generations of high voltage (HV) and medium voltage (MV) CoolGaN TM devices, enabling customers to use GaN in voltage classes from 40 V to 700 V. The devices are built using Infineon’s 8-inch foundry processes.

Ansys launched Ansys Access on Microsoft Azure to provide pre-configured simulation products optimized for HPC on Azure infrastructure.

Foxconn Industrial Internet used Keysight Technology’s Open RAN Studio solution to certify an outdoor Open Radio Unit (O-RU).

Andes Technology announced an SoC and development board for the development and porting of large RISC-V applications.

MediaTek uncorked a pair of mobile chipsets built on a 4nm process that use an octa-core CPU consisting of 4X Arm Cortex-A78 cores operating at up to 2.5GHz paired with 4X Arm Cortex-A55 cores.

The NVIDIA H200 Blackwell platform is expected to begin shipping in Q3 of 2024 and will be available to data centers by Q4, according to TrendForce.

A room-temperature direct fusion hybrid bonding system from Be Semiconductor has shipped to the NHanced advanced packaging facility in North Carolina. The new system offers faster throughput for copper interconnects with submicron pad sizes, greater accuracy and reduced warpage.

Markets and Money

Frore Systems raised $80 million for its solid-state active cooling module, which removes heat from the top of a chip without fans. The device in systems ranging from notebooks and network edge gateways to data centers.

Axus Technology received $12.5 million in capital equity funding to make its chemical mechanical planarization (CMP) equipment for semiconductor wafer polishing, thinning, and cleaning, including of silicon carbide (SiC) wafers.

Elon Musk’s xAI announced a series B funding round of $6 billion.

Micron was ordered to pay $445 million in damages to Netlist for patent infringement of the company’s DDR4 memory module technology between 2021 and 2024.

Global revenue from AI semiconductors is predicted to total $71 billion in 2024, up 33% from 2023, according to Gartner. In 2025, it is expected to jump to $91.9 billion. The value of AI accelerators used in servers is expected to total $21 billion in 2024 and reach $33 billion by 2028.

NAND flash revenue was $14.71 billion in Q1 2024, an increase of 28.1%, according to TrendForce.

The optical transceiver market dipped from $11 billion in 2022 to $10.9 billion in 2023, but it is predicted to reach $22.4 billion by 2029, driven by AI, 800G applications, and the transition to 200G/lane ecosystem technologies, reports Yole.

Yole also found that ultra-wideband technical choices and packaging types used by NXP, Apple, and Qorvo vary considerably, ranging from 7nm to 90nm, with both CMOS and finFET transistors.

The global market share of GenAI-capable smartphones increased to 6% in Q1 2024 from 1.3% in the previous quarter, reports Counterpoint. The premium segment accounted for over 70% of sales with Samsung on top and contributing 58%. Meanwhile, global foldable smartphone shipments were up 49% YoY in Q1 2024, led by Huawei, HONOR, and Motorola.

Security

The National Science Foundation awarded Worcester Polytechnic Institute researcher Shahin Tajik almost $0.6 million to develop new technologies to address hardware security vulnerabilities.

The Hyperform consortium was formed to develop European sovereignty in post-quantum cryptography, funded by the French government and EU credits. Members include IDEMIA Secure Transactions, CEA Leti, and the French cybersecurity agency (ANSSI).

In security research:

• University of California Davis and University of Arizona researchers proposed a framework leveraging generative pre-trained transformer (GPT) models to automate the obfuscation process.
• Columbia University and Intel researchers presented a secure digital low dropout regulator that integrates an attack detector and a detection-driven protection scheme to mitigate correlation power analysis.
• Pohang University of Science and Technology (POSTECH) researchers analyzed threshold switch devices and their performance in hardware security.

The U.S. Defense Advanced Research Projects Agency (DARPA) seeks proposals for its AI Quantified program to develop technology to help deploy generative AI safely and effectively across the Department of Defense (DoD) and society.

Vanderbilt University and Oak Ridge National Laboratory (ORNL) partnered to develop dependable AI for national security applications.

The Cybersecurity and Infrastructure Security Agency (CISA) issued a number of alerts/advisories.

Research and Training

New York continues to amp up their semiconductor offerings. NY CREATES and Raytheon unveiled a semiconductor workforce training program. And Syracuse  University is hosting a free virtual course focused on the semiconductor industry this summer.

In research news:

• A team of researchers at MIT and other universities found that extreme temperatures up to 500°C did not significantly degrade GaN materials or contacts.
• University of Cambridge researchers developed adaptive and eco-friendly sensors that can be directly and imperceptibly printed onto biological surfaces, such as a finger or flower petal.
• Researchers at Rice University and Hanyang University developed an elastic material that moves like skin and can adjust its dielectric frequency to stabilize RF communications and counter disruptive frequency shifts that interfere with electronics when a substrate is twisted or stretched, with potential for stretchable wearable electronic devices.

The National Science Foundation (NSF) awarded $36 million to three projects chosen for their potential to revolutionize computing. The University of Texas at Austin-led project aims to create a next-gen open-source intelligent and adaptive OS. The Harvard University-led project targets sustainable computing. The University of Massachusetts Amherst-led project will develop computational decarbonization.

Quantum

Singapore will invest close to S$300 million (~$222 million) into its National Quantum Strategy to support the development and deployment of quantum technologies, including an initiative to design and build a quantum processor within the country.

Several quantum partnerships were announced:

• Riverlane and Alice & Bob will integrate Riverlane’s quantum error correction stack within Alice & Bob’s larger quantum computing system based on cat qubit technology.
• New York University and the University of Copenhagen will collaborate to explore the viability of hybrid superconductor-semiconductor quantum materials for the production of quantum chips and integration with CMOS processes.
• NXP, eleQtron, and ParityQC showed off a full-stack, ion-trap based quantum computer demonstrator for Germany’s DLR Quantum Computing Initiative.
• Photonic says it demonstrated distributed entanglement between quantum modules using optically-linked silicon spin qubits with a native telecom networking interface as part of a quantum internet effort with Microsoft.
• Classiq and HPE say they developed a rapid method for solving large-scale combinatorial optimization problems by combining quantum and classical HPC approaches.

Events and Further Reading

Find upcoming chip industry events here, including:

Upcoming webinars are here, including integrated SLM analytics solution, prototyping and validation of perception sensor systems, and improving PCB designs for performance and reliability.

Semiconductor Engineering’s latest newsletters:

Automotive, Security and Pervasive Computing
Systems and Design
Low Power-High Performance
Test, Measurement and Analytics
Manufacturing, Packaging and Materials

The post Chip Industry Week In Review appeared first on Semiconductor Engineering.

President Biden will raise the tariff rate on Chinese semiconductors from 25% to 50% by 2025, among other measures to protect U.S. businesses from China’s trade practices. Also, as part of President Biden’s AI Executive Order, the Administration released steps to protect workers from AI risks, including human oversight of systems and transparency about what systems are being used.

Intel is in advanced talks with Apollo Global Management for the equity firm to provide more than $11 billion to build a fab in Ireland, reported the Wall Street Journal. Also, Intel’s Foundry Services appointed Kevin O’Buckley as the senior vice president and general manager.

Polar is slated to receive up to $120 million in CHIPS Act funding to establish an independent American foundry in Minnesota. The company expects to invest about $525 million in the expansion of the facility over the next two years, with a $75 million investment from the State of Minnesota.

Arm plans to develop AI chips for launch next year, reports Nikkei Asia.

South Korea is planning a support package worth more than 10 trillion won ($7.3 billion) aimed at chip materials, equipment makers, and fabless companies throughout the semiconductor supply chain, according to Reuters.

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Global

Edwards opened a new facility in Asan City, South Korea. The 15,000m² factory provides a key production site for abatement systems, and integrated vacuum and abatement systems for semiconductor manufacturing.

France’s courtship with mega-tech is paying off.  Microsoft is investing more than US $4 billion to expand its cloud computing and AI infrastructure, including bringing up to 25,000 advanced GPUs to the country by the end of 2025. The “Choose France” campaign also snagged US $1.3 billion from Amazon for cloud infrastructure expansion, genAI and more.

Toyota, Nissan, and Honda are teaming up on AI and chips for next-gen cars with support from Japan’s Ministry of Economy, Trade and Industry, (METI), reports Nikkei Asia.

Meanwhile, IBM and Honda are collaborating on long-term R&D of next-gen technologies for software-defined vehicles (SDV), including chiplets, brain-inspired computing, and hardware-software co-optimization.

Siemens and Foxconn plan to collaborate on global manufacturing processes in electronics, information and communications technology, and electric vehicles (EV).

TSMC confirmed a Q424 construction start date for its first European plant in Dresden, Germany.

Amazon Web Services (AWS) plans to invest €7.8 billion (~$8.4B) in the AWS European Sovereign Cloud in Germany through 2040. The system is designed to serve public sector organizations and customers in highly regulated industries.

In-Depth

Semiconductor Engineering published its Low Power-High Performance newsletter this week, featuring these stories:

• • Will Domain-Specific ICs Become Ubiquitous?
  • Running More Efficient AI/ML Code With Neuromorphic Engines
  • Power/Performance Costs In Chip Security

And this week’s Test, Measurement & Analytics newsletter featured these stories:

• Using Predictive Maintenance To Boost IC Manufacturing Efficiency
• The Future Of Fault Coverage In Chips
• Doing More At Functional Test

Markets and Money

The U.S. National Institute of Standards and Technology (NIST) awarded more than $1.2 million to 12 businesses in 8 states under the Small Business Innovation Research (SBIR) Program to fund R&D of products relating to cybersecurity, quantum computing, health care, semiconductor manufacturing, and other critical areas.

Engineering services and consulting company Infosys completed the acquisition of InSemi Technology, a provider of semiconductor design and embedded software development services.

The quantum market, which includes quantum networking and sensors alongside computing, is predicted to grow from $838 million in 2024 to $1.8 billion in 2029, reports Yole.

Shipments of OLED monitors reached about 200,000 units in Q1 2024, a year over year growth of 121%, reports TrendForce.

Global EV sales grew 18% in Q1 2024 with plug-in hybrid electric vehicles (PHEV) sales seeing 46% YoY growth and battery electric vehicle (BEV) sales growing just 7%, according to Counterpoint. China leads global EV sales with 28% YoY growth, while the US grew just 2%. Tesla saw a 9% YoY drop, but topped BEV sales with a 19% market share. BYD grew 13% YoY and exported about 100,000 EVs with 152% YoY growth, mainly in Southeast Asia.

DeepX raised $80.5 million in Series C funding for its on-device NPU IP and AI SoCs tailored for applications including physical security, robotics, and mobility.

MetisX raised $44 million in Series A funding for its memory solutions built on Compute Express Link (CXL) for accelerating large-scale data processing applications.

Security

While security experts have been warning of a growing threat in electronics for decades, there have been several recent fundamental changes that elevate the risk.

Synopsys and the Ponemon Institute released a report showing 54% of surveyed organizations suffered a software supply chain attack in the past year and 20% were not effective in their response. And 52% said their development teams use AI tools to generate code, but only 32% have processes to evaluate it for license, security, and quality risks.

Researchers at Ruhr University Bochum and TU Darmstadt presented a solution for the automated generation of fault-resistant circuits (AGEFA) and assessed the security of examples generated by AGEFA against side-channel analysis and fault injection.

TXOne reported on operational technology security and the most effective method for preventing production interruptions caused by cyber-attacks.

CrowdStrike and NVIDIA are collaborating to accelerate the use of analytics and AI in cybersecurity to help security teams combat modern cyberattacks, including AI-powered threats.

The National Institute of Standards and Technology (NIST) finalized its guidelines for protecting sensitive data, known as controlled unclassified information, aimed at organizations that do business with the federal government.

The Defense Advanced Research Projects Agency (DARPA) awarded BAE Systems a $12 million contract to solve thermal challenges limiting electronic warfare systems, particularly in GaN transistors.

Sigma Defense won a $4.7 million contract from the U.S. Army for an AI-powered virtual training environment, partnering with Brightline Interactive on a system that uses spatial computing and augmented intelligence workflows.

SkyWater’s advanced packaging operation in Florida has been accredited as a Category 1A Trusted Supplier by the Defense Microelectronics Activity (DMEA) of the U.S. Department of Defense (DoD).

Videos of two CWE-focused sessions from CVE/FIRST VulnCon 2024 were made available on the CWE YouTube Channel.

The Cybersecurity and Infrastructure Security Agency (CISA) issued a number of alerts/advisories.

Supercomputing

Supercomputers are battling for top dog.

The Frontier supercomputer at Oak Ridge National Laboratory (ORNL) retained the top spot on the Top500 list of the world’s fastest systems with an HPL score of 1.206 EFlop/s. The as-yet incomplete Aurora system at Argonne took second place, becoming the world’s second exascale system at 1.012 EFlop/s. The Green500 list, which tracks energy efficiency of compute, saw three new entrants take the top places.

Cerebras Systems, Sandia National Laboratory, Lawrence Livermore National Laboratory, and Los Alamos National Laboratory used Cerebras’ second generation Wafer Scale Engine to perform atomic scale molecular dynamics simulations at the millisecond scale, which they claim is 179X faster than the Frontier supercomputer.

UT Austin‘s Stampede3 Supercomputer is now in full production, serving the open science community through 2029.

Education and Training

SEMI announced the SEMI University Semiconductor Certification Programs to help alleviate the workforce skills gap. Its first two online courses are designed for new talent seeking careers in the industry, and experienced workers looking to keep their skills current.  Also, SEMI and other partners launched a European Chip Skills Academy Summer School in Italy.

Siemens created an industry credential program for engineering students that supplements a formal degree by validating industry knowledge and skills. Nonprofit agency ABET will provide accreditation. The first two courses are live at the University of Colorado Boulder (CU Boulder) and a series is planned with Pennsylvania State University (Penn State).

Syracuse University launched a $20 million Center for Advanced Semiconductor Manufacturing, with co-funding from Onondaga County.

Starting young is a good thing.  An Arizona school district, along with the University Of Arizona,  is creating a semiconductor program for high schoolers.

Product News

Siemens and Sony partnered to enable immersive engineering via a spatial content creation system, NX Immersive Designer, which includes Sony’s XR head-mounted display. The integration of hardware and software gives designers and engineers natural ways to interact with a digital twin. Siemens also extended its Xcelerator as a Service portfolio with solutions for product engineering and lifecycle management, cloud-based high-performance simulation, and manufacturing operations management. It will be available on Microsoft Azure, as well.

Advantest announced the newest addition to its portfolio of power supplies for the V93000 EXA Scale SoC test platform. The DC Scale XHC32 power supply offers 32 channels with single-instrument total current of up to 640A.

Fig. 1: Advantest’s DC Scale XHC32. Source: Advantest

Infineon released its XENSIV TLE49SR angle sensors, which can withstand stray magnetic fields of up to 8 mT, ideal for applications of safety-critical automotive chassis systems.

Google debuted its sixth generation Cloud TPU, 4.7X faster and 67% more energy-efficient than the previous generation, with double the high-bandwidth memory.

X-Silicon uncorked a RISC-V vector CPU, coupled with a Vulkan-enabled GPU ISA and AI/ML acceleration in a single processor core, aimed at embedded and IoT applications.

IBM expanded its Qiskit quantum software stack, including the stable release of its SDK for building, optimizing, and visualizing quantum circuits.

Northeastern University announced the general availability of testing and integration solutions for Open RAN through the Open6G Open Testing and Integration Center (Open 6G OTIC).

Research

The University of Glasgow received £3 million (~$3.8M) from the Engineering and Physical Sciences Research Council (EPSRC)’s Strategic Equipment Grant scheme to help establish “Analogue,” an Automated Nano Analysing, Characterisation and Additive Packaging Suite to research silicon chip integration and packaging.

EPFL researchers developed scalable photonic ICs, based on lithium tantalate.

DISCO developed a way to increase the diameter of diamond wafers that uses the KABRA process, a laser ingot slicing method.

CEA-Leti developed two complementary approaches for high performance photon detectors — a mercury cadmium telluride-based avalanche photodetector and a superconducting single photon detector.

Toshiba demonstrated storage capacities of over 30TB with two next-gen large capacity recording technologies for hard disk drives (HDDs): Heat Assisted Magnetic Recording (HAMR) and Microwave Assisted Magnetic Recording (MAMR).

Caltech neuroscientists reported that their brain-machine interface (BMI) worked successfully in a second human patient, following 2022’s first instance, proving the device is not dependent on one particular brain or one location in a brain.

Linköping University researchers developed a cheap, sustainable battery made from zinc and lignin, while ORNL researchers developed carbon-capture batteries.

Events and Further Reading

Find upcoming chip industry events here, including:

Upcoming webinars are here.

Semiconductor Engineering’s latest newsletters:

Automotive, Security and Pervasive Computing
Systems and Design
Low Power-High Performance
Test, Measurement and Analytics
Manufacturing, Packaging and Materials

The post Chip Industry Week In Review appeared first on Semiconductor Engineering.

Atomic layer deposition (ALD) used to be considered too slow to be of practical use in semiconductor manufacturing, but it has emerged as a critical tool for both transistor and interconnect fabrication at the most advanced nodes.

ALD can be speeded up somewhat, but the real shift is the rising value of precise composition and thickness control at the most advanced nodes, which makes the extra time spent on deposition worthwhile.

ALD is a close cousin of chemical vapor deposition, initially introduced in high volume to the semiconductor industry for hafnium oxide (high-k) gate dielectrics. Both CVD and ALD are inherently conformal processes. Deposition occurs on all surfaces exposed to a precursor gas. In ALD, though, the reaction is self-limiting.

The process works like this: First, a precursor gas (A) is introduced into the process chamber, where it adsorbs onto all available substrate sites. No further adsorption occurs once all surface sites are occupied. An inert purge gas, typically nitrogen or argon, flushes out any remaining precursor gas, then a second precursor (B) is introduced. Precursor B reacts with the chemisorbed precursor A to produce the desired film. Once all of the adsorbed molecules are consumed, the reaction stops. After a second purge step, the cycle repeats.

ALD opportunities expand as features shrink
The step-by-step nature of ALD is both its strength and its weakness. Depositing one monolayer at a time gives manufacturers extremely precise thickness control. Using different precursor gases in different ratios can tune the film composition. Unfortunately, the repeated precursor/purge gas cycles take a lot of time. In an interview, CEA-Leti researcher Rémy Gassilloud estimated that in a single wafer process, two minutes per wafer is the maximum cost-effective process time. But two minutes is only enough time to deposit about a 2nm-thick film.

Some process adjustments can improve throughput. Silicon dioxide ALD often uses large furnaces to process many wafers at once. Plasma activation can ionize reagents and accelerate film formation. Still, Gassilloud estimates that 10nm is the maximum practical thickness for ALD films.

As transistors shrink, though, the number of layers in that thickness range is increasing. Transistor structures also are becoming more complex, requiring deposition on vertical surfaces, into deep trenches, and other places not readily accessible by line-of-sight PVD methods. Replacement gates for gate-all-around transistors, for instance, need a process that can fill nanometer-scale cavities.

As noted above, HfO₂ was the first successful application of ALD in semiconductor manufacturing. Its precursors, HfCl₄ and water, are both chemically simple small molecules, whose by-products are volatile and easily removed. Such simple chemistries are the exception, though. ALD of silicon dioxide typically uses aminosilane precursors.⁠[1] Metal nitrides often have complex metal-organic precursor gases. Gassilloud noted that ligands might be added to a precursor molecule to change its vapor pressure or reactivity, or to facilitate adhesion to the substrate. In selective deposition processes, discussed below, ligands might improve selectivity between growth and non-growth surfaces. These larger molecules can be difficult to insinuate into smaller features, and byproducts can be difficult to remove. Complex byproducts can also become a contamination source.

One of the advantages of ALD is its very low process temperature, typically between 200°C and 300°C. It is thermally compatible with both transistor and interconnect processes in CMOS, as well as with deposition on plastic and other novel substrates. Even so, Aditya Kumar and colleagues at GlobalFoundries showed that precise temperature control is important.^⁠[2] TDMAT (tetrakis- dimethylamino titanium) condensation in a TiN deposition process was a significant source of particle defects. To maintain the desired process temperature, both the precursor and purge gas temperatures matter. Introducing cold purge gas into a warm process chamber can cause rapid condensation.

As ALD has become a mainstream process, the industry has found applications for it beyond core device materials, in a variety of sacrificial and spacer layers. For example, double- and quadruple-patterning schemes often use ALD for “pitch-doubling.” By depositing a spacer material on either side of a patterned “mandrel,” then removing the mandrel, the process can cut the original pitch in half without the need for an additional, more costly lithography step.^⁠[3]

Fig. 1: Self-aligned double patterning with ALD spacers. Source: Creative Commons

Depositing a doped oxide on the vertical silicon fins of a finFET device is a less directional and less damaging alternative to ion implantation.[^⁠4]

Selective deposition brings lateral control
These last two examples depend on surface characteristics to mediate deposition. A precursor might adhere more readily to a hard mask than to the underlying material. The vertical face of a silicon fin might offer more (or fewer) adsorption sites than the horizontal face. Selective deposition on more complicated structures may require a pre-deposited growth template, functionalizing substrate regions to encourage or discourage growth. Selective deposition is especially important in interconnect applications. In general, though, a comprehensive review by Rong Chen and colleagues at Huazhong University of Science and Technology explained that selective deposition methods need to replenish the template material as the film grows while needing a mechanism to selectively remove the unwanted material.⁠[5]

For example, tungsten preferentially deposits on silicon relative to SiO₂, but the selectivity diminishes after only a few cycles. Researchers at North Carolina State University successfully re-passivated the oxide by incorporating hydrogen into the tungsten precursor.[⁠6] Similarly, a group at Eindhoven University of Technology found that SiO₂ preferentially deposited on SiO₂ relative to other oxides for only 10 to 15 cycles. A so-called ABC-cycle — adding acetylacetone (“Inhibitor A”) as an inhibitor every 5 to 10 cycles — restored selectivity.⁠[7]

Alternatively, or in addition, atomic layer etching (ALE) might be used to remove unwanted material. ALE operates in the same step-by-step manner as ALD. The first half of a cycle reacts with the existing surface, weakening the bond to the underlying material. Then, a second step — typically ion bombardment — removes the weakened layer. For example, in ALE etching of silicon, chlorine gas reacts with the surface to form various SiCl_x compounds. The chlorination process weakens the inter-silicon bonds between the surface and the bulk, and the chlorinated layer is easily sputtered away. The layer-by-layer nature of ALE depends on preferential removal of the surface material relative to the bulk (SiCl_x vs. Si in this case). The “ALE window” is the combination of energy and temperature at which the surface layer is completely removed without damaging the underlying material.

Somewhat counter-intuitively, Keren Kanarik and colleagues at Lam Research found that higher ion energies actually expanded the ALE window for silicon etching. High ion energies with short exposure times delayed the onset of silicon sputtering relative to conventional RIE.[8]

Adding and subtracting, one atomic layer at a time
For a long time, the semiconductor industry has been looking for alternatives to process schemes that deposit material, pattern it, then etch most of it away. Wouldn’t it be simpler to only deposit the material we will ultimately need? Meanwhile, atomic layer deposition has been filling the spaces under nanosheets and inside cavities. Bulk deposition and etch tools are still with us, and will be for the foreseeable future. In more and more cases, though, those tools provide the frame while ALD and ALE processes fill in the details.

Correction: Corrected attribution of the work on ABC cycles and selective deposition of SiO₂.

References

1. Wenling Li, et al., “Impact of aminosilane and silanol precursor structure on atomic layer deposition process,”Applied Surface Science, Vol 621, 2023,156869, https://doi.org/10.1016/j.apsusc.2023.156869.
2. Kumar, et al., “ALD TiN Surface Defect Reduction for 12nm and Beyond Technologies,” 2020 31st Annual SEMI Advanced Semiconductor Manufacturing Conference (ASMC), Saratoga Springs, NY, USA, 2020, pp. 1-4, doi: 10.1109/ASMC49169.2020.9185271.
3. Shohei Yamauchi, et al., “Extendibility of self-aligned type multiple patterning for further scaling”, Proc. SPIE 8682, Advances in Resist Materials and Processing Technology XXX, 86821D (29 March 2013); https://doi.org/10.1117/12.2011953
4. Kalkofen, et al., “Atomic layer deposition of phosphorus oxide films as solid sources for doping of semiconductor structures,” 2018 IEEE 18th International Conference on Nanotechnology (IEEE-NANO), Cork, Ireland, 2018, pp. 1-4, doi: 10.1109/NANO.2018.8626235.
5. Rong Chen et al., “Atomic level deposition to extend Moore’s law and beyond,” 2020 Int. J. Extrem. Manuf. 2 022002 DOI 10.1088/2631-7990/ab83e0
6. B Kalanyan, et al., “Using hydrogen to expand the inherent substrate selectivity window during tungsten atomic layer deposition,” 2016 Chem. Mater. 28 117–26 https://doi.org/10.1021/acs.chemmater.5b03319
7. Alfredo Mameli et al., “Area-Selective Atomic Layer Deposition of SiO2 Using Acetylacetone as a Chemoselective Inhibitor in an ABC-Type Cycle” ACS Nano 2017, 11, 9, 9303–9311. https://doi.org/10.1021/acsnano.7b04701
8. Keren J. Kanarik, et al., “Universal scaling relationship for atomic layer etching,” J. Vac. Sci. Technol. A 39, 010401 (2021); doi: 10.1116/6.0000762

The post Enabling Advanced Devices With Atomic Layer Processes appeared first on Semiconductor Engineering.

Atomic layer deposition (ALD) used to be considered too slow to be of practical use in semiconductor manufacturing, but it has emerged as a critical tool for both transistor and interconnect fabrication at the most advanced nodes.

ALD can be speeded up somewhat, but the real shift is the rising value of precise composition and thickness control at the most advanced nodes, which makes the extra time spent on deposition worthwhile.

ALD is a close cousin of chemical vapor deposition, initially introduced in high volume to the semiconductor industry for hafnium oxide (high-k) gate dielectrics. Both CVD and ALD are inherently conformal processes. Deposition occurs on all surfaces exposed to a precursor gas. In ALD, though, the reaction is self-limiting.

The process works like this: First, a precursor gas (A) is introduced into the process chamber, where it adsorbs onto all available substrate sites. No further adsorption occurs once all surface sites are occupied. An inert purge gas, typically nitrogen or argon, flushes out any remaining precursor gas, then a second precursor (B) is introduced. Precursor B reacts with the chemisorbed precursor A to produce the desired film. Once all of the adsorbed molecules are consumed, the reaction stops. After a second purge step, the cycle repeats.

ALD opportunities expand as features shrink
The step-by-step nature of ALD is both its strength and its weakness. Depositing one monolayer at a time gives manufacturers extremely precise thickness control. Using different precursor gases in different ratios can tune the film composition. Unfortunately, the repeated precursor/purge gas cycles take a lot of time. In an interview, CEA-Leti researcher Rémy Gassilloud estimated that in a single wafer process, two minutes per wafer is the maximum cost-effective process time. But two minutes is only enough time to deposit about a 2nm-thick film.

Some process adjustments can improve throughput. Silicon dioxide ALD often uses large furnaces to process many wafers at once. Plasma activation can ionize reagents and accelerate film formation. Still, Gassilloud estimates that 10nm is the maximum practical thickness for ALD films.

As transistors shrink, though, the number of layers in that thickness range is increasing. Transistor structures also are becoming more complex, requiring deposition on vertical surfaces, into deep trenches, and other places not readily accessible by line-of-sight PVD methods. Replacement gates for gate-all-around transistors, for instance, need a process that can fill nanometer-scale cavities.

As noted above, HfO₂ was the first successful application of ALD in semiconductor manufacturing. Its precursors, HfCl₄ and water, are both chemically simple small molecules, whose by-products are volatile and easily removed. Such simple chemistries are the exception, though. ALD of silicon dioxide typically uses aminosilane precursors.⁠[1] Metal nitrides often have complex metal-organic precursor gases. Gassilloud noted that ligands might be added to a precursor molecule to change its vapor pressure or reactivity, or to facilitate adhesion to the substrate. In selective deposition processes, discussed below, ligands might improve selectivity between growth and non-growth surfaces. These larger molecules can be difficult to insinuate into smaller features, and byproducts can be difficult to remove. Complex byproducts can also become a contamination source.

One of the advantages of ALD is its very low process temperature, typically between 200°C and 300°C. It is thermally compatible with both transistor and interconnect processes in CMOS, as well as with deposition on plastic and other novel substrates. Even so, Aditya Kumar and colleagues at GlobalFoundries showed that precise temperature control is important.^⁠[2] TDMAT (tetrakis- dimethylamino titanium) condensation in a TiN deposition process was a significant source of particle defects. To maintain the desired process temperature, both the precursor and purge gas temperatures matter. Introducing cold purge gas into a warm process chamber can cause rapid condensation.

As ALD has become a mainstream process, the industry has found applications for it beyond core device materials, in a variety of sacrificial and spacer layers. For example, double- and quadruple-patterning schemes often use ALD for “pitch-doubling.” By depositing a spacer material on either side of a patterned “mandrel,” then removing the mandrel, the process can cut the original pitch in half without the need for an additional, more costly lithography step.^⁠[3]

Fig. 1: Self-aligned double patterning with ALD spacers. Source: Creative Commons

Depositing a doped oxide on the vertical silicon fins of a finFET device is a less directional and less damaging alternative to ion implantation.[^⁠4]

Selective deposition brings lateral control
These last two examples depend on surface characteristics to mediate deposition. A precursor might adhere more readily to a hard mask than to the underlying material. The vertical face of a silicon fin might offer more (or fewer) adsorption sites than the horizontal face. Selective deposition on more complicated structures may require a pre-deposited growth template, functionalizing substrate regions to encourage or discourage growth. Selective deposition is especially important in interconnect applications. In general, though, a comprehensive review by Rong Chen and colleagues at Huazhong University of Science and Technology explained that selective deposition methods need to replenish the template material as the film grows while needing a mechanism to selectively remove the unwanted material.⁠[5]

For example, tungsten preferentially deposits on silicon relative to SiO₂, but the selectivity diminishes after only a few cycles. Researchers at North Carolina State University successfully re-passivated the oxide by incorporating hydrogen into the tungsten precursor.[⁠6] Similarly, a group at Argonne National Laboratory found that SiO₂ preferentially deposited on SiO₂ relative to other oxides for only 10 to 15 cycles. Adding acetylacetone (“Precursor C”) as an inhibitor every 5 to 10 cycles — restored selectivity.⁠[7]

Alternatively, or in addition, atomic layer etching (ALE) might be used to remove unwanted material. ALE operates in the same step-by-step manner as ALD. The first half of a cycle reacts with the existing surface, weakening the bond to the underlying material. Then, a second step — typically ion bombardment — removes the weakened layer. For example, in ALE etching of silicon, chlorine gas reacts with the surface to form various SiCl_x compounds. The chlorination process weakens the inter-silicon bonds between the surface and the bulk, and the chlorinated layer is easily sputtered away. The layer-by-layer nature of ALE depends on preferential removal of the surface material relative to the bulk (SiCl_x vs. Si in this case). The “ALE window” is the combination of energy and temperature at which the surface layer is completely removed without damaging the underlying material.

Somewhat counter-intuitively, Keren Kanarik and colleagues at Lam Research found that higher ion energies actually expanded the ALE window for silicon etching. High ion energies with short exposure times delayed the onset of silicon sputtering relative to conventional RIE.[8]

Adding and subtracting, one atomic layer at a time
For a long time, the semiconductor industry has been looking for alternatives to process schemes that deposit material, pattern it, then etch most of it away. Wouldn’t it be simpler to only deposit the material we will ultimately need? Meanwhile, atomic layer deposition has been filling the spaces under nanosheets and inside cavities. Bulk deposition and etch tools are still with us, and will be for the foreseeable future. In more and more cases, though, those tools provide the frame while ALD and ALE processes fill in the details.

References

1. Wenling Li, et al., “Impact of aminosilane and silanol precursor structure on atomic layer deposition process,”Applied Surface Science, Vol 621, 2023,156869, https://doi.org/10.1016/j.apsusc.2023.156869.
2. Kumar, et al., “ALD TiN Surface Defect Reduction for 12nm and Beyond Technologies,” 2020 31st Annual SEMI Advanced Semiconductor Manufacturing Conference (ASMC), Saratoga Springs, NY, USA, 2020, pp. 1-4, doi: 10.1109/ASMC49169.2020.9185271.
3. Shohei Yamauchi, et al., “Extendibility of self-aligned type multiple patterning for further scaling”, Proc. SPIE 8682, Advances in Resist Materials and Processing Technology XXX, 86821D (29 March 2013); https://doi.org/10.1117/12.2011953
4. Kalkofen, et al., “Atomic layer deposition of phosphorus oxide films as solid sources for doping of semiconductor structures,” 2018 IEEE 18th International Conference on Nanotechnology (IEEE-NANO), Cork, Ireland, 2018, pp. 1-4, doi: 10.1109/NANO.2018.8626235.
5. Rong Chen et al., “Atomic level deposition to extend Moore’s law and beyond,” 2020 Int. J. Extrem. Manuf. 2 022002 DOI 10.1088/2631-7990/ab83e0
6. B Kalanyan, et al., “Using hydrogen to expand the inherent substrate selectivity window during tungsten atomic layer deposition,” 2016 Chem. Mater. 28 117–26 https://doi.org/10.1021/acs.chemmater.5b03319
7. Yanguas-Gil A, Libera J A and Elam J W, “Modulation of the growth per cycle in atomic layer deposition using reversible surface functionalization,” 2013 Chem. Mater. 25 4849–60 https://doi.org/10.1021/cm4029098
8. Keren J. Kanarik, et al., “Universal scaling relationship for atomic layer etching,” J. Vac. Sci. Technol. A 39, 010401 (2021); doi: 10.1116/6.0000762

The post Enabling Advanced Devices With Atomic Layer Processes appeared first on Semiconductor Engineering.

By Adam Kovac, Karen Heyman, and Liz Allan.

India approved the construction of two fabs and a packaging house, for a total investment of about $15.2 billion, according to multiple sources. One fab will be jointly owned by Tata and Taiwan’s Powerchip. The second fab will be a joint investment between CG Power, Japan’s Renesas Electronics, and Thailand’s Stars Microelectronics. Tata will run the packaging facility, as well. India expects these efforts will add 20,000 advanced technology jobs and 60,000 indirect jobs, according to the Times of India. The country has been talking about building a fab for at least the past couple of decades, but funding never materialized.

The U.S. Department of Commerce (DoC) issued a CHIPS Act-based Notice of Funding Opportunity for R&D to establish and accelerate domestic capacity for advanced packaging substrates and substrate materials. The U.S. Secretary of Commerce said the government is prioritizing CHIPS Act funding for projects that will be operational by 2030 and anticipates America will produce 20% of the world’s leading-edge logic chips by the end of the decade.

The top three foundries plan to implement backside power delivery as soon as the 2nm node, setting the stage for faster and more efficient switching in chips, reduced routing congestion, and lower noise across multiple metal layers. But this novel approach to optimizing logic performance depends on advances in lithography, etching, polishing, and bonding processes.

Intel spun out Altera as a standalone FPGA company, the culmination of a rebranding and reorganization of its former Programmable Solutions Group. The move follows Intel’s decision to keep Intel Foundry at arm’s length, with a clean line between the foundry and the company’s processor business.

Multiple new hardware micro-architecture vulnerabilities were published in the latest Common Weakness Enumeration release this week, all related to transient execution (CWE 1420-1423).

The U.S. Office of the National Cyber Director (ONCD) published a technical report calling for the adoption of memory safe programming languages, aiming to reduce the attack surface in cyberspace and anticipate systemic security risk with better diagnostics. The DoC also is seeking information ahead of an inquiry into Chinese-made connected vehicles “to understand the extent of the technology in these cars that can capture wide swaths of data or remotely disable or manipulate connected vehicles.”

Quick links to more news:

Design and Power
Manufacturing and Test
Automotive
Security
Pervasive Computing and AI
Events

Design and Power

Micron began mass production of a new high-bandwidth chip for AI. The company said the HBM3E will be a key component in NVIDIA’s H2000 Tensor Core GPUs, set to begin shipping in the second quarter of 2024. HBM is a key component of 2.5D advanced packages.

Samsung developed a 36GB HBM3E 12H DRAM, saying it sets new records for bandwidth. The company achieved this by using advanced thermal compression non-conductive film, which allowed it to cram 12 layers into the area normally taken up by 8. This is a novel way of increasing DRAM density.

Keysight introduced QuantumPro, a design and simulation tool, plus workflow, for quantum computers. It combines five functionalities into the Advanced Design System (ADS) 2024 platform. Keysight also introduced its AI Data Center Test Platform, which includes pre-packaged benchmarking apps and dataset analysis tools.

Synopsys announced a 1.6T Ethernet IP solution, including 1.6T MAC and PCS Ethernet controllers, 224G Ethernet PHY IP, and verification IP.

Tenstorrent, Japan’s Leading-Edge Semiconductor Technology Center (LSTC) , and Rapidus are co-designing AI chips. LSTC will use Tenstorrent’s RISC-V and Chiplet IP for its forthcoming edge 2nm AI accelerator.

This week’s Systems and Design newsletter features these top stories:

• 2.5D Integration: Big Chip Or Small PCB: Defining whether a 5D device is a PCB shrunk to fit into a package or a chip that extends beyond the limits of a single die can have significant design consequences.
• Commercial Chiplets: Challenges of establishing a commercial chiplet.
• Accellera Preps New Standard For Clock-Domain Crossing: New standard aims to streamline the clock-domain crossing flow.
• Thinking Big: From Chips To Systems: Aart de Geus discusses the shift from chips to systems, next-generation transistors, and what’s required to build multi-die devices.
• Integration challenges for RISC-V: Modifying the source code allows for democratization of design, but it adds some hurdles for design teams (video).

Demand for high-end AI servers is driven by four American companies, which will account for 60% of global demand in 2024, according to Trendforce. NVIDIA is projected to continue leading the market, with AMD closing the gap due its lower cost model.

The EU consortium PREVAIL is accepting design proposals as it seeks to develop next-gen edge-AI technologies. Anchors include CEA-Leti, Fraunhofer-Gesellschaft, imec, and VTT, which will use their 300mm fabrication, design, and test facilities to validate prototypes.

Siemens joined an initiative to expand educational opportunities in the semiconductor space around the world. The Semiconductor Education Alliance was launched by Arm in 2023 and focuses on helping teach skills in IC design and EDA.

Q-CTRL announced partnerships with six firms that it says will expand access to its performance-management software and quantum technologies. Wolfram, Aqarios, and qBraid will integrate Q-CTRL’s Fire Opal technology into their products, while Qblox, Keysight, and Quantware will utilize Q-CTRL’s Boulder Opal hardware system.

NTT, Red Hat, NVIDIA, and Fujitsu teamed up to provide data pipeline acceleration and contain orchestration technologies targeted at real-time AI analysis of massive data sets at the edge.

Manufacturing and Test

The U.S. Department of Energy (DOE)’s Office of Electricity launched the American-Made Silicon Carbide (SiC)  Packaging Prize. This $2.25 million contest invites competitors to propose, design, build, and test state-of-the-art SiC semiconductor packaging prototypes.

Applied Materials introduced products and solutions for patterning issues in the “angstrom era,” including line edge roughness, tip-to-tip spacing limitations, bridge defects, and edge placement errors.

imec reported progress made in EUV processes, masks and metrology in preparation for high-NA EUV. It also identified advanced node lithography and etch related processes that contribute the most to direct emissions of CO2, along with proposed solutions.

proteanTecs will participate in the Arm Total Design ecosystem, which now includes more than 20 companies united around a charter to accelerate and simplify the development of custom SoCs based on Arm Neoverse compute subsystems.

NikkeiAsia took an in-depth look at Japan’s semiconductor ecosystem and concluded it is ripe for revival with investments from TSMC, Samsung, and Micron, among others. TrendForce came to a similar conclusion, pointing to the fast pace of Japan’s resurgence, including the opening of TSMC’s fab.

‍FormFactor closed its sale of its Suzhou and Shanghai companies to Grand Junction Semiconductor for $25M in cash.

The eBeam Initiative celebrated its 15th anniversary and welcomed a new member, FUJIFILM. The group also uncorked its fourth survey of its members technology using deep learning in the photomask-to-wafer manufacturing flow.

Automotive

Apple shuttered its electric car project after 10 years of development. The chaotic effort cost the company billions of dollars, according to The New York Times.

Infineon released new automotive programmable SoCs with fifth-gen human machine interface (HMI) technology, offering improved sensitivity in three packages. The MCU offers up to 84 GPIOs and 384 KB of flash memory. The company also released automotive and industrial-grade 750V G1 discrete SiC MOSFETs aimed at applications such as EV charging, onboard chargers, DC-DC converters, energy, solid state circuit breakers, and data centers.

Cadence expanded its Tensilica IP portfolio to boost computation for automotive sensor fusion applications. Vision, radar, lidar, and AI processing are combined in a single DSP for multi-modal, sensor-based system designs.

Ansys will continue translating fast computing into fast cars, as the company’s partnership with Oracle Red Bull Racing was renewed. The Formula 1 team uses Ansys technology to improve car aerodynamics and ensure the safety of its vehicles.

Lazer Sport adopted Siemens’ Xcelerator portfolio to connect 3D design with 3D printing for prototyping and digital simulation of its sustainable KinetiCore cycling helmet.

The chair of the U.S. Federal Communications Commission (FCC) suggested automakers that sell internet-connected cars should be subject to a telecommunications law aiming to protect domestic violence survivors, reports CNBC. This is due to emerging cases of stalking through vehicle location tracking technology and remote control of functions like locking doors or honking the horn.

BYD‘s CEO said the company does not plan to enter the U.S. market because it is complicated and electrification has slowed down, reports Yahoo Finance. Meanwhile, the first shipment of BYD vehicles arrived in Europe, according to DW News.

Ascent Solar Technologies’ solar module products will fly on NASA’s upcoming Lightweight Integrated Solar Array and AnTenna (LISA-T) mission.

Security

Researchers at Texas A&M University and the University of Delaware proposed the first red-team attack on graph neural network (GNN)-based techniques in hardware security.

A panel of four experts discuss mounting concerns over quantum security, auto architectures, and supply chain resiliency.

Synopsys released its ninth annual Open Source Security and Risk Analysis report, finding that 74% of code bases contained high-risk open-source vulnerabilities, up 54% since last year.

President Biden issued an executive order to prevent the large-scale transfer of Americans’ personal data to countries of concern. Types of data include genomic, biometric, personal health, geolocation, financial, and other personally identifiable information, which bad actors can use to track and scam Americans.

The National Institute of Standards and Technology (NIST) released Cybersecurity Framework (CSF) 2.0 to provide a comprehensive view for managing cybersecurity risk.

The EU Agency for Cybersecurity (ENISA) published a study on best practices for cyber crisis management, saying the geopolitical situation continues to impact the cyber threat landscape and planning for threats and incidents is vital for crisis management.

The U.S. Department of Energy (DOE) announced $45 million to protect the energy sector from cyberattacks.

The National Security Agency (NSA), the Federal Bureau of Investigation (FBI), and others published an advisory on Russian cyber actors using compromised routers.  Also the Cybersecurity and Infrastructure Security Agency (CISA), the UK National Cyber Security Centre (NCSC), and partners advised of tactics used by Russian Foreign Intelligence Service cyber actors to gain initial access into a cloud environment.

CISA, the FBI, and the Department of Health and Human Services (HHS) updated an advisory concerning the ALPHV Blackcat ransomware as a service (RaaS), which primarily targets the healthcare sector.

CISA also published a guide to support university cybersecurity clinics and issued other alerts.

Pervasive Computing and AI

Renesas expanded its RZ family of MPUs with a single-chip AI accelerator that offers 10 TOPS per watt power efficiency and delivers AI inference performance of up to 80 TOPS without a cooling fan. The chip is aimed at next-gen robotics with vision AI and real-time control.

Infineon launched dual-phase power modules to help data centers meet the power demands of AI GPU platforms. The company also released a family of solid-state isolators to deliver faster switching with up to 70% lower power dissipation.

Fig. 1: Infineon’s dual phase power modules: Source: Infineon

Amber Semiconductor announced a reference design for brushless motor applications using its AC to DC conversion semiconductor system to power ST‘s STM32 MCUs.

Micron released its universal flash storage (UFS) 4.0 package at just 9×13 mm, built on 232-layer 3D NAND and offering up to 1 terabyte capacity to enable next-gen phone designs and larger batteries.

LG and Meta teamed up to develop extended reality (XR) products, content, services, and platforms within the virtual space.

Microsoft and Mistral AI partnered to accelerate AI innovation and to develop and deploy Mistral’s next-gen large language models (LLMs).

Microsoft’s vice chair and president announced the company’s AI access principles, governing how it will operate AI datacenter infrastructure and other AI assets around the world.

Singtel and VMware partnered to enable enterprises to manage their connectivity and cloud infrastructure through the Singtel Paragon platform for 5G and edge cloud.

Keysight was selected as the Test Partner for the Deutsche Telekom Satellite NB-IoT Early Adopter Program, providing an end-to-end NB-IoT NTN testbed that allows designers and developers to validate reference designs for solutions using 3GPP Release 17 (Rel-17) NTN standards.

Global server shipments are predicted to increase by 2.05% in 2024, with AI servers accounting for about 12%, reports TrendForce. Also, the smartphone camera lens market is expected to rebound in 2024 with 3.8% growth driven by AI-smartphones, to reach about 4.22 billion units, reports TrendForce.

Yole released a smartphone camera comparison report with a focus on iPhone evolution and analysis of the structure, design, and teardown of each camera module, along with the CIS dimensions, technology node, and manufacturing processes.

Counterpoint released a number of 2023 reports on smartphone shipments by country and operator migrations to 5G.

Events

Find upcoming chip industry events here, including:

Upcoming webinars are here, including topics such as digital twins, power challenges in data centers, and designing for 112G interface compliance.

Further Reading and Newsletters

Read the latest special reports and top stories, or check out the latest newsletters:

Systems and Design
Low Power-High Performance
Test, Measurement and Analytics
Manufacturing, Packaging and Materials
Automotive, Security and Pervasive Computing

The post Chip Industry Week In Review appeared first on Semiconductor Engineering.

Successive versions of vertical transistors are emerging as the likely successor to finFETs, combining lower leakage with significant area reduction.

A stacked nanosheet transistor, introduced at N3, uses multiple channel layers to maintain the overall channel length and necessary drive current while continuing to reduce the standard cell footprint. The follow-on technology, the CFET, pushes further up the z axis, stacking n-channel and p-channel transistors on top of each other, rather than side by side.

In work presented at December’s IEEE Electron Device Meeting, researchers at TSMC estimated that CFETs give a 1.5X to 2X overall size reduction at constant gate dimensions. [1] Those are significant area benefits for any digital logic, but manufacturing these new transistor structures will be a challenge.

Monolithic 3D integration is the simplest integration scheme, and the one likely to see production first. In monolithic 3D integration, the entire structure is assembled on a single piece of silicon. This approach can also be used to fabricate compute-in-memory designs where memory devices are fabricated as part of the metallization layers for a conventional CMOS circuit. While individual layers in monolithic 3D designs can incorporate new technologies — the integration of ReRAM devices, for example — the overall CMOS flow is preserved. All of the materials and processes used must be compatible with that rubric.

Adding more nanosheets for complementary devices
The overall process in this kind of scheme is similar to a stacked nanosheet transistor flow. It starts with a stack of eight or more alternating silicon and silicon germanium layers (four pairs), compared to a stacked nanosheet NFET or PFET, which might have only four such layers (two pairs). In a CFET flow, however, middle dielectric layer is inserted halfway through the stack.

This layer, separating the n-type and p-type transistors, is probably the most important difference from a standard nanosheet transistor flow. To minimize parasitic capacitance, the middle dielectric layer should be as thin as possible, said imec’s Naoto Horiguchi. If it’s too thin, though, edge placement errors can cause isolation failures, landing contacts for the top devices onto bottom devices. [2]

In TSMC’s process, the Si/SiGe superlattice includes a high-germanium SiGe layer as a placeholder for the middle dielectric. After the source/drain etch, a highly selective etch removes this layer and oxidizes the silicon on either side of it to form the middle dielectric.

The inner spacer recess etch, which follows middle dielectric formation in the TSMC process, indents the SiGe layers relative to the silicon nanosheets, defining the gate length and junction overlap.

While TSMC emphasized it has not yet made fully metallized integrated CFET circuits, it did report that more than 90% of the transistors survived.

Fig. 1: TSMC used monolithic integration to stack NFET and PFET devices. [1]

Depositing the nanosheet stack is straightforward. Etching it with the precision required is not. A less-than-vertical etch profile will change the relative channel lengths of the top and bottom devices, leading to asymmetric switching characteristics.

Stacking wafers for more flexibility
The alternative, sequential 3D integration is a bit more flexible. While monolithic 3D integration uses a single device layer, sequential 3D integration bonds an additional tier on top of the first. Sequential 3D integration is different from three-dimensional wafer-level packaging and chip stacking, though. In WLP, the component devices are finished, passivated, and tested. The component chips are fully functional as independent circuits. In sequential 3D integration, the two tiers are part of a single integrated circuit.

Often, though not always, the second tier is an unprocessed bare wafer with no devices at all. Ionut Radu, director of research and external collaborations at Soitec, said his company used its SmartCut process to transfer sub-micron silicon layers. [3] One of the advantages of sequential integration, though, is that it opens the door to other possibilities. For example, the second layer could use a different silicon lattice orientation to facilitate stress engineering for improved carrier mobility. It also could use an alternative channel material, such as GaAs or a two-dimensional semiconductor. And up until the transfer occurs, processing of the second wafer has no effect on the thermal budget of the first.

After bonding, the second tier’s process temperature generally must remain below 500° C. Tadeu Mota-Frutuoso, process integration engineer at CEA-Leti, said researchers were able to achieve this benchmark in a conventional CMOS process by using laser annealing for the source/drain activation steps. [4]

While sequential 3D integration can be used to realize CFET devices, the top layers also can contain independent circuitry. Still, as in monolithic integration, the dielectric layer between the two circuit tiers is a critical process step. Analysts at KAIST found that reducing the thickness of the interlayer dielectric improves heat dissipation. It also facilitates the use of a bottom gate to control the top tier devices. On the other hand, the dielectric layer lies at the interface between the original wafer and the transferred layer. Thickness control depends on the polishing step used to prepare the transfer surface. Such precise control is extremely challenging for CMP. [5]

Re-driving wafers without contamination
While the second circuit tier can be added at any point in the process flow, the insertion point constrains not only the first and second tier devices, but also the fab as a whole. When the second layer does not yet contain devices, alignment to the first layer is relatively easy. In contrast, Horiguchi said, aligning one device wafer on top of another imposes an area penalty to accommodate potential overlay error. The total device thickness of sequential 3D structures tends to be greater, as well.

Returning a first-tier wafer with contacts and other metallization to FEOL tools for fabrication of a second transistor layer poses a substantial cross contamination risk. Even if the top surface is well encapsulated, Mota-Frutuoso explained in an interview that the sidewalls and bevels of the bottom tier can still expose metal layers to FEOL processes. CEA-Leti’s proposed bevel contamination wrap (BCW) scheme first cleans the wafer edge, then encapsulates it and the sidewall in a protective oxide layer.

Fig. 2: CEA-Leti’s sequential 3D integration stacked silicon CMOS on an industrial 28nm FDSOI wafer. [4]

Controlling heat dissipation
Heat dissipation is a major challenge for both monolithic and sequential 3D devices. Generalizations are difficult because thermal characteristics depend on the specific integration scheme and even the circuit design. Wei-Yen Woon, senior manager at TSMC, and his colleagues evaluated AlN and diamond as possible thermal dissipation layers. While both have been used in power devices, they are new to CMOS process flows. They achieved good quality columnar AlN films with a low temperature sputtering process, though the columnar structure did impede in-plane heat transport. While diamond offers extremely high thermal conductivity, it also can require extremely high process temperatures. The TSMC group deposited thin films with acceptable quality at BEOL compatible temperatures by using pre-deposited diamond nuclei, but they have not yet attempted to integrate these films with working devices.^[6]

What’s next?
In the short term, monolithic 3D integration offers a relatively straightforward path to CFET fabrication, building on existing nanosheet transistor process flows. Even proponents of sequential 3D integration expect the monolithic approach to reach production first. For the longer term, though, the ability to use a completely different material for the second device layer gives device designers many more process optimization knobs.

However it is achieved, the idea that active devices no longer need to confine themselves to a single planar layer has implications far beyond logic transistors. From compute-in-memory modules to image sensors, 3D integration is an important tool for “More than Moore” devices.

References

^[1] S. Liao et al., “Complementary Field-Effect Transistor (CFET) Demonstration at 48nm Gate Pitch for Future Logic Technology Scaling,” 2023 International Electron Devices Meeting (IEDM), San Francisco, CA, USA, 2023, pp. 1-4, doi: 10.1109/IEDM45741.2023.10413672.

^[2] N. Horiguchi et al., “3D Stacked Devices and MOL Innovations for Post-Nanosheet CMOS Scaling,” 2023 International Electron Devices Meeting (IEDM), San Francisco, CA, USA, 2023, pp. 1-4, doi: 10.1109/IEDM45741.2023.10413701.

^[3] I. Radu et al., “Ultimate Layer Stacking Technology for High Density Sequential 3D Integration,” 2023 International Electron Devices Meeting (IEDM), San Francisco, CA, USA, 2023, pp. 1-4, doi: 10.1109/IEDM45741.2023.10413807.

^[4] T. Mota-Frutuoso et al., “3D sequential integration with Si CMOS stacked on 28nm industrial FDSOI with Cu-ULK iBEOL featuring RO and HDR pixel,” 2023 International Electron Devices Meeting (IEDM), San Francisco, CA, USA, 2023, pp. 1-4, doi: 10.1109/IEDM45741.2023.10413864.

^[5] S. K. Kim et al., “Role of Inter-Layer Dielectric on the Electrical and Heat Dissipation Characteristics in the Heterogeneous 3D Sequential CFETs with Ge p-FETs on Si n-FETs,” 2023 International Electron Devices Meeting (IEDM), San Francisco, CA, USA, 2023, pp. 1-4, doi: 10.1109/IEDM45741.2023.10413845.

^[6] W. Y. Woon et al., “Thermal dissipation in stacked devices,” 2023 International Electron Devices Meeting (IEDM), San Francisco, CA, USA, 2023, pp. 1-4, doi: 10.1109/IEDM45741.2023.10413721.

The post Building CFETs With Monolithic And Sequential 3D appeared first on Semiconductor Engineering.