Showing posts with label DSA - diercted self-assembly. Show all posts
Showing posts with label DSA - diercted self-assembly. Show all posts

Saturday, August 31, 2024

Breakthrough by Japanese Researchers - Block Copolymer Enables Ultra-Fine Semiconductor Patterns with 7.6 nm Half-Pitch

Scientists at Tokyo Institute of Technology and Tokyo Ohka Kogyo have developed a novel block copolymer (BCP) that could significantly advance semiconductor manufacturing by enabling finer circuit patterns through directed self-assembly (DSA). This new BCP, derived from a chemically tailored version of polystyrene-block-poly(methyl methacrylate) (PS-b-PMMA), self-assembles into lamellar structures with a half-pitch size of just 7.6 nanometers. This surpasses the capabilities of conventional BCPs, which struggle to achieve sub-10 nm features, and represents one of the smallest reported half-pitch sizes in the world for thin-film lamellar structures.

a Schematic of the DSA process using a PS-b-PGFM on a chemically patterned Si substrate. AFM phase images of a b PS-b-PGFM19-23 film on an NL35-modified DSA substrate (Ls = 90 nm) after annealing at 240 °C for 5 min, c PS-b-PGFM19-10 film on an NL38-modified DSA substrate (Ls = 84 nm) after annealing at 230 °C for 5 min, and d PS-b-PGFM18-11 film on an NL38-modified DSA substrate (Ls = 90 nm) after annealing at 230 °C for 5 min. All thin films are 19-nm thick and were etched using O2 plasma for 10 s prior to AFM.

The research, published in *Nature Communications*, highlights the potential of this new BCP to push the boundaries of miniaturization in electronics, which is crucial for the continued advancement of semiconductor technology. The tailored copolymer, PS-b-PGFM, exhibits reliable and reproducible self-assembly into extremely small nanometric patterns, making it a promising template for lithographic processes. As the demand for smaller feature sizes in semiconductor devices grows, this breakthrough could pave the way for next-generation Logic and Memory components that all need to continuously scale to smaller critical dimensions.

Sources:

Advances in Semiconductor Patterning: New Block Copolymer Achieves 7.6nm Line Width - Semiconductor Digest (semiconductor-digest.com)

Chemically tailored block copolymers for highly reliable sub-10-nm patterns by directed self-assembly | Nature Communications

Friday, April 19, 2024

Intel's Strategic Leap with 14A Node and DSA: Pioneering Next-Gen Semiconductor Manufacturing

Semi Analysis recently published a deeper dive into of Directed Self Assembly (DSA) and prospects of Intel using it at their 14A node (Link below). Intel's latest efforts in semiconductor manufacturing have brought considerable attention to its 18A node, yet it's the 14A node that is most important according to the analysis for the success of Intel Foundry's IDM 2.0 strategy. While the industry watches the ongoing discussions around the merits of TSMC's N2 and Intel’s 18A technologies, Intel is quietly setting a foundational stage with its 14A node, aiming to solidify customer trust and secure critical, high-value chip projects for the future. A key element in Intel's strategy may be the adoption of DSA that could significantly reduce lithography costs. DSA utilizes the self-organizing properties of block copolymers (BCPs) that assemble into predetermined patterns when guided by an underlying template. This approach promises to lower the doses required in extreme ultraviolet (EUV) lithography, allowing for more efficient patterning at reduced costs.

However, integrating DSA into commercial manufacturing involves challenges such as defectivity and pattern limitations, which could hinder its adoption. So I looked more into historical patent filings and found that reveal a typical hype cycle with increased filings during periods of peak expectations, followed by a decline as practical challenges emerged. Intel and TSMC have been consistently filing DSA patents, indicating sustained investment and belief in DSA's potential. Merck, among other chemical suppliers, has significantly increased patent filings, aligning with technological advancements in DSA. Please find on overview below.


It is well known that Intel plans to be the first major company to implement ASML’s high-NA EUV lithography scanners in high volume, despite the higher costs associated with single exposure high-NA systems compared to low-NA double patterning. It was also recently reported on X and other places that ASML is delivering a High-NA System to another player. SemiAnalysis argues that, the economic challenge posed by high-NA technology is addressed through the integration of DSA, which can improve the final pattern quality and dramatically reduce the necessary dose, thus potentially making high-NA economically more viable.

The benefits of DSA are significant: 

  • The ability to produce finer features with lower line edge roughness and increased throughput, thanks to its ability to heal discrepancies in the EUV guide patterns. 
  • Substantial cost savings and improved yield, especially for layers critical to the performance of advanced logic chips (bigger dies like AI accelerators).

However, DSA's integration into a commercial manufacturing environment is not without risks. The risks associated with Intel's adoption of DSA include:

  • The primary risk with any new patterning technology is defectivity, for DSA it is linked to the chemical purity of the block copolymers (BCP). Synthesizing BCP to extremely high purities is challenging, and any inhomogeneity directly impacts the critical dimension (CD), leading to defects. Trace metals need to be below 10 parts-per-trillion, and filtering out organic impurities is difficult, impacting the viability of DSA for mass production. My assessment - Expect this to come from a MERCK or a Japanese chemical vendor.
  • DSA is inherently limited to producing 1D line/space patterns or contact hole arrays, restricted to a single pitch per layer. This complicates the integration with other process technologies that might require more diverse patterning capabilities. However, these issues have potential solutions similar to those used in multi-patterning schemes.
  • Despite the theoretical benefits and recent advances in DSA, it remains largely untested in high-volume, leading-edge manufacturing. Intel is pioneering the use in high-NA scenarios, but the broader adoption across the industry, including by competitors like TSMC who are also developing DSA, remains uncertain. 

Source: Intel’s 14A Magic Bullet: Directed Self-Assembly (DSA) (semianalysis.com)

So let´s do the Patbase Test - how does this hold out if we dig into historical and current patent filing by the suspects!

Yes indeed, we have seen much increased filing the past decade or so representing a typical hype cycle. The hype cycle is a model developed by Gartner that describes the progression of a technology from inception to widespread adoption and maturity. It typically consists of five phases: the Technology Trigger, Peak of Inflated Expectations, Trough of Disillusionment, Slope of Enlightenment, and Plateau of Productivity. So for DSA in semiconductor manufacturing, the technology first garnered attention when its potential applications in advanced lithography were identified (2000-2010), marking the Technology Trigger. Interest surged about 2011, leading to a Peak of Inflated Expectations around 2016/2017, evidenced by a spike in patent filings as companies raced to capitalize on the emerging technology. However, as practical and economic challenges such as defectivity and integration complexities became evident, the enthusiasm waned, and DSA entered the Trough of Disillusionment. During this phase, the technology's limitations led to a decline in interest as initial expectations were not met. Over time, as more sustainable applications and improvements are developed, DSA may progress into the Slope of Enlightenment, where understanding and optimization occur as described in the assessment by SemiAnalysis, before finally reaching the Plateau of Productivity in the years to come, where it becomes a standard part of semiconductor manufacturing processes. This progression through the hype cycle reflects the typical maturation path of innovative technologies in the industry. Please note that there is a delay in patent filing data of up to 18 months so 2022, 2023 and 2024 are not complete yet.

Patent filing since 2000 in DSA (Patbase, 2024-04-19)

2. Yes, Intel is actively filing DSA patents and in the lead, and so is TSMC, along with other key players in the ecosystem. Over the past decade, the pattern of DSA patent filings has been quite revealing. Initially, GlobalFoundries and IBM in Upstate New York were early filers. GlobalFoundries ceased their filings around the time they decided not to pursue 7 nm and nodes below. IBM also stopped filing after completing their 2 nm demonstration on 300 mm wafers in 2021. Main contenders Intel and TSMC have been consistently filing DSA patents throughout the hype cycle and have continued to do so. Notably, there has been a clear acceleration in Intel's patent filings since 2019, although there was a slight drop during the COVID-19 lockdowns. Looking at chemical suppliers, Merck has taken the lead, with increased filings beginning in parallel with Intel from 2019 onwards, and accelerating until today. Other suppliers such as JSR, Shin-Etsu, and Brewer Science are also active in the DSA space. In the segment of wafer equipment OEMs, Tokyo Electron and SCREEN have been dominant. However, SCREEN appears to have recently exited the game.

DSA Patent filing last decade (Patbase , 2024-04-19)

In Summary - good assessment by SemiAnalysis and i passes the Patbase Test!






Thursday, August 24, 2023

An Update on Directed Self-Assembly (DSA) for Advancing Micro and Nano Fabrication

Revolutionizing fabrication, Directed Self-Assembly (DSA) innovates micro to nano devices and materials. It leverages block co-polymer morphology for precise patterns and guides micro/nano particles, enhancing manufacturing. In semiconductors, DSA addresses lithography challenges, while Imec's research showcases DSA-EUV synergy for defect-free outcomes. Complex rectification processes, illustrated by Imec, spotlight improved Critical Dimension Uniformity and Pattern Placement Error control. As DSA advances, its collaboration with EUV promises precision, efficiency, and innovation across industries.

DSA has emerged as a groundbreaking technique for mass-producing micro to nano devices and materials with precision and efficiency. This method harnesses the inherent properties of materials to assemble them into intricate structures, revolutionizing manufacturing processes across various industries.

DSA leverages block co-polymer morphology to create patterns, enhancing feature control and shape accuracy. This involves guiding the assembly of micro and nano particles to achieve desired structures, made possible by the precise control of surface interactions and polymer thermodynamics. The key advantage of DSA is its ability to create structures at remarkably small scales, enabling advancements in diverse fields.

In the semiconductor industry, DSA offers a new perspective on lithography challenges. Despite initial setbacks, DSA is being revisited to address critical issues such as stochastic defects in extreme ultraviolet (EUV) lithography. These defects, which can contribute significantly to patterning errors, have led semiconductor manufacturers to explore DSA as a solution to rectify these problems. Notably, DSA is not replacing traditional methods but rather enhancing them. It is being integrated with existing manufacturing processes to enable increased resolution and precision, all while reducing costs.

However, challenges persist in integrating DSA into high-volume manufacturing. Defect control remains a primary concern, as the technology strives to meet industry standards of minimal defectivity. Common defects include line bridging, collapse, bubbles, and dislocations. Efforts are ongoing to optimize annealing temperature, etching methods, and film thickness to reduce these defects. Another challenge is the complexity of pattern inspection, which demands accurate metrology methods. Researchers are exploring machine learning-based approaches to automate the inspection process and achieve higher throughput.

Despite these challenges, DSA is being applied to various applications beyond semiconductors. Tissue engineering benefits from the precision of directed assembly, enabling the controlled organization of cells into desired micro-structures. In nanotechnology, DSA facilitates the creation of precise nanostructures, leading to advancements in areas such as graphene nanoribbon arrays and thin-film quantum materials.

Revolutionizing EUV Lithography with Directed Self-Assembly (DSA)

EUV lithography has revolutionized semiconductor manufacturing but comes with its share of challenges, particularly in addressing line roughness and stochastic defects. DSA has now gained attention as a potential game-changer to tackle these issues in EUV lithography.

Recent research from Imec sheds light on the promising synergy between EUV and DSA in overcoming lithography challenges. In the study titled "EUV Lithography Line Space Pattern Rectification Using Block Copolymer Directed Self-Assembly: A Roughness and Defectivity Study," led by Julie Van Bel and team, the researchers explored the combination of DSA with EUV. Their findings indicate that this integration surpasses DSA processes based on Immersion lithography, offering lower line width roughness and freedom from dislocation defects.

Another study, "Mitigating Stochastics in EUV Lithography by Directed Self-Assembly," led by Lander Verstraete and collaborators, delved into the application of DSA to mitigate stochastic defects in EUV processing.

Imec's approach to rectify defects in EUV lithography involves intricate processes, as illustrated in Figures below. In the top Figure, the team outlines the process for rectifying defects in EUV Line/Space Patterns using DSA. Meanwhile, the lower Figure details the rectification process for defects in EUV Contact Patterns.


Imec's approach to rectify defects in EUV lithography involves intricate processes, as illustrated in the figures below. In the top figure, the team outlines the process for rectifying defects in EUV Line/Space Patterns using Directed Self-Assembly (DSA). Meanwhile, the lower figure details the rectification process for defects in EUV Contact Patterns. These illustrations highlight the potential of DSA in enhancing lithographic precision, addressing challenges related to line roughness and stochastic defects, and achieving improved Local Critical Dimension Uniformity (LCDU) and Pattern Placement Error control in semiconductor manufacturing.

The results are particularly promising for line/spaces at a 28nm pitch, primarily addressing bridge defects. However, at a 24nm pitch, further improvement is necessary due to an excess of bridge defects. Notably, the type and frequency of defects correlate with the formulation of the block copolymer and the duration of the annealing process.

For contact arrays, the combination of EUV and DSA demonstrates improved Local Critical Dimension Uniformity (LCDU) and Pattern Placement Error. This advancement also enables the use of a lower dose, contributing to enhanced precision and efficiency in semiconductor manufacturing.

Imec's research underscores the potential of DSA to revolutionize EUV lithography by addressing line roughness and stochastic defects. The successful integration of EUV and DSA holds the promise of enhancing semiconductor manufacturing processes, achieving higher precision, and enabling the production of advanced devices with improved quality. As researchers continue to refine these methods, the collaboration between EUV and DSA is set to shape the future of lithography and microfabrication.

In conclusion, DSA is revitalizing micro and nano fabrication by offering accurate and efficient methods for mass production. While challenges like defect control and metrology persist, DSA's potential to shape the future of industries such as semiconductors, biomedicine, and nanotechnology is undeniable. As research continues to refine DSA processes and overcome hurdles, its role in advancing technology and innovation is set to expand further.

Directed Self-Assembly Finds Its Footing (semiengineering.com)

SPIE 2023 – imec Preparing for High-NA EUV - SemiWiki

Directed assembly of micro- and nano-structures - Wikipedia

Saturday, November 10, 2018

Directed self-assembly of block copolymers for 7 nanometre FinFET technology and beyond

Globalfoundries recently announced that they have dropped all plans on putting 7 nm FinFET technology in production (LINK). Presumably this means that any advanced development for 7nm and beyond patterning has been stopped as well. In any case here is an excellent publication submitted before that announcment coming from the collaborative development from some of the most advanced semiconductor development centers in the USA - IBM Research at Albany NanoTech, TEL Technology Center, America in Albany, GlobalFoundries, and IBM Research TJ Watson in Yorktown Heights and IBM Research Almaden, San Jose.



They use different versions of directed self assembly (DSA) of block co-polymers (BCP) and spacer defined double patterning. ALD is used for spacers as well as very thin ALD SiN hardmasks. All this is all done without EUV like in the Samsung 2nd Generation 7nm FinFET or self aligned quadruple patterning (SAQP) like in the Intel 10 nm FinFET) - Impressive!

Some details are given in the Supplementary info (below).

Directed self-assembly of block copolymers for 7 nanometre FinFET technology and beyond


Nature Electronics volume 1, pages562–569 (2018)

Supplementary information : LINK (OPEN)