EUV Tech: A Leader In Metrology Equipment For Enabling Semiconductor Manufacturing Using Extreme Ultraviolet Lithography

By Amit Chowdhry ● Jul 11, 2023 

EUV Tech is known as a global leader in the production of metrology equipment to enable leading-edge semiconductor manufacturing using extreme ultraviolet lithography (EUVL). To learn more about the company Pulse 2.0 interviewed EUV Tech CEO Dr. Patrick Naulleau.

Dr. Naulleau’s Background

Dr. Naulleau is a technologist at heart and has been working on EUV lithography and metrology his entire career, ever since joining Lawrence Berkeley National Laboratory (LBNL) in 1997 right out of grad school to work at the world-renowned Center for X-ray Optics (CXRO).

“My area of expertise is advanced optical systems and techniques, and my career focus was always on developing bleeding-edge instrumentation and tools in support of our industry partners. In 2010, I took on the role of Director at CXRO and further built up and led the team that developed both the world’s first high-NA patterning tool, as well as the world’s first high-NA EUV mask microscope,” said Dr. Naulleau. “These facilities now serve as the benchmark for industry development of next-generation EUV tools. Throughout my time at LBNL, I also kept a close eye on all the exciting work going on at EUV Tech and was honored to take the position of CEO here in August 2022.”

Formation Of EUV Tech

The company was founded back in 1997 by two pioneering researchers in the field of EUV: Rupert Perera and James Underwood – who were both at the Center for X-Ray Optics (CXRO) at the time. They recognized very early on that in order for EUV Lithography to succeed, critical EUV metrology techniques would need to be deployed across the industry as opposed to relying on mega-scale accelerator-based light sources at National Laboratories.

“At the time, one of the most critical metrology tasks was the ability to measure the performance of the special nanolayered mirrors, called multilayers, needed for EUV,” Dr. Naulleau noted. “To meet this need, the founders developed a standalone tool called a EUV Reflectometer, based on an ultra-compact, highly stable, laser-plasma light source replacing the arena-sized accelerator-based light source previously used for these types of measurements. Over time, EUV Tech’s Reflectometer became the standard for EUV mask measurements and we partnered with all the major semiconductor research centers and manufacturers to enable the commercialization of EUV masks. EUV Tech later also branched out to develop tools for EUV resist testing and pellicle metrology.”

Core Products

What are EUV Tech’s core products and features? Dr. Naulleau replied:

“EUV Tech was created on the premise of generating EUV light and building unique measurement instruments using that light. EUV Tech’s founding product, the EUV Reflectometer, is a mainstay for world-leading mask manufacturers and research facilities and is recognized as a critical metrology tool for ensuring the quality of EUV photomasks. The EUV Reflectometer, first placed into production in 2003, measures the performance of multilayer mirrors tailored for EUV lithography. The types of measurements it performs include determining exactly how much EUV light is reflected by the mirror, as well as determining the exact color(s) of the reflected light. Since its original release, the EUV Reflectometer has experienced a technological leap into the world of high-volume manufacturing (HVM) as a variant of the original tool with improved cleanliness and drastically improved measurement performance in terms of accuracy and repeatability. The HVM EUV Reflectometer was introduced to the market in August 2015 as the first commercial at-wavelength EUV metrology tool put into a production environment. No product can match how precise this piece of equipment is for handling such an essential step in the quality assurance of the EUV mask blank.

Another game-changing product is our new EUV N&K and Phase Measurement Tool introduced to the market during the latter part of 2022. While the current generation of EUV masks are designed to locally control the intensity of the reflected light, the next generation of masks will also need to locally control the time delay of the reflected light. As the saying goes, ‘What cannot be measured, cannot be controlled,’ thus we now need tools to measure a mask’s ability to delay light. A material’s ability to delay light is characterized by the index of refraction of the material (N) and the actual delay of the light is called ‘Phase shift.’ The measure of a material’s ability to absorb light is ‘K.’ Similar to the Reflectometer before, the EUV Tech EUV N&K and Phase Measurement Tool deliver to the chip manufacturing industry a capability that was previously limited to arena-sized synchrotrons.

Another tool we are really excited about is our zone plate-based EUV mask defect review microscope. A zone plate is an ultra-compact nanofabricated lens that can achieve essentially perfect imaging in the EUV and soft-x-ray regimes. These lenses can be less than 1 mm in size, which allows us to build an incredibly high-performing microscope in a very compact footprint. This microscope is used to directly image tiny, i.e., nanoscale defects on EUV masks. Defect imaging on masks is an essential capability in the chip manufacturing process because the ‘mask’ represents the ‘master’ that is ultimately used by the lithography tool for printing every single chip.

Finally, we also build a suite of tools that are used to characterize EUV pellicles. A pellicle is an ultra-thin protective window that is mounted above the mask to protect the critical mask from defects falling on it. Because this window needs to transmit almost all the EUV light with almost zero reflection, measuring with the types of EUV tools that we have perfected over the years has become essential.”

Challenges Faced

What are some of the challenges EUV Tech faced in building the company? “The evolution of EUV and the road to production has been quite a journey. When the company was founded in 1997, the expectation was that EUV Lithography would be in use for high-volume chip manufacturing just seven years later in 2004. Obviously, things did not work out that way and we needed to adapt in order to survive based on a much smaller customer base for an extended period of time. We did so by staying laser-focused on the R&D community and understanding and meeting their needs for EUV metrology instrumentation, while at the same time carefully controlling our cost structure,” Dr. Naulleau acknowledged. “During this period, we established partnerships with consortia, such as SEMATECH in the US, IMEC in Europe, and EIDEC in Japan. We also used this time as an opportunity to continuously refine our products, keeping pace with the evolving needs dictated by the shrink of the insertion node for EUV. In 2004, the entry node was expected to be 100 nm devices, whereas, in reality, the actual entry node for EUV turned out to be 5 nm.”

Dr. Naulleau pointed out that things really changed for EUV Tech in terms of growth in 2016 — when EUV started breaking ground in high-volume production applications. Fortunately, EUV Tech’s continued innovation paid off and they were ready with a 5-nm node compatible High-Volume Manufacturing EUV Reflectometer to meet the chip manufacturing industry’s needs.

“Needless to say, company growth was definitely a challenge from 2004 to 2016, but we were very fortunate to have founders who never lost faith and did everything possible to keep the company viable and innovating,” Dr. Naulleau added. “Ironically, current challenges are very much the opposite. The semiconductor industry and chip manufacturing has absolutely become a hot topic in the last few years. The new challenges are staffing to meet both increased product output, as well as customer support over a rapidly expanding tool base. Other challenges include space, both in terms of office space for the team as well as manufacturing space, supply chain delays, and increased product portfolio. Although we are now faced with several new challenges, thankfully, these are good challenges to have.”

Evolution Of EUV Tech’s Technology

How has EUV Tech’s technology evolved since launching? “As I discussed earlier, because of the long road to commercialization of EUV lithography, the early days of EUV Tech were focused on developing technology relevant to the pure research and R&D communities while always keeping an eye on the ultimate goal of high-volume production tools. Evolving the technology to production tools meant increasing our technology focus on particle cleanliness, tool reliability, and availability,” Dr. Naulleau shared. “And of course, our technology has continuously evolved to keep pace with the never-ending march of Moore’s Law, which in the metrology world translates to ever-increasing demands on measurement accuracy and precision. Another way our technology has significantly evolved is in breadth. EUV Tech was founded based on a single product, the EUV Reflectometer, but we have now evolved our core technologies to enable the much broader tool portfolio we offer today.”

Biggest Milestones

What have been some of EUV Tech’s biggest milestones?

— 1997: Development of ultra-stable EUV plasma metrology light source

— 2000: Patented EUV zone plate microscope

— 2003: The first production-ready EUV Reflectometer

— 2005: EUV Reflectometer wins R&D Magazine R&D100 Award

— 2007: Development of the world’s first tool for EUV resist outgassing and surface contamination measurements

— 2015: HVM EUV Reflectometer released to a production environment

— 2017: Commercial delivery of the world’s first EUV Pellicle Transmission Measurement tool

— 2020: Commercial delivery of the world’s first plasma-based full-field zone plate EUV mask microscope

— 2022: Commercial delivery of the world’s first plasma-based EUV n/k/phase tool

— 2023: Series A funding from Intel Capital

Customer Success Stories

When I asked Dr. Naulleau about customer success stories, he revealed that EUV Tech’s partnership with Intel has been integral to the success of the company.

“Intel’s belief in our capabilities and support early on with orders for prototype tools helped us develop our next-generation semiconductor metrology equipment and fuel the growth of our product portfolio. Intel has helped both our innovations in products and allowed us to hire talented individuals to bring those concepts to life,” Dr. Naulleau highlighted. “Another partnership we are particularly proud of is supporting the Center of X-ray Optics at Lawrence Berkeley National Laboratory (LBNL) in their endeavor to couple a stand-alone plasma source to their world’s only EUV high-NA microfield exposure tool. LBNL turned to us based on our significant experience in integrating Energetiq, Inc. high-power EUV light sources into resist testing tools. This partnership has allowed LBNL to decouple their highly sought-after EUV high-NA patterning facility from the synchrotron light source thereby increasing the yearly capacity of the facility by more than a factor of 3.”

Funding

In early March, EUV Tech raised a Series A funding round. That funding round was led by Intel Capital and Intel Capital Managing Director Sean Doyle joined the board of directors. That funding round will be used for improving and expanding current product offerings, increasing R&D resources and facilities, and supporting the global customer base.

Future Company Goals

What are some of EUV Tech’s future company goals? “Since our founding, EUV Tech’s mission has not wavered in either intent or goal – to set the benchmark for the strategic and rapid development of precision-built EUV metrology equipment. Our expertise in EUV, soft-x-ray instrumentation, vacuum systems, clean transfer, and full-production system integration allows for rapid development of new EUV metrology tools and improvements to existing tools,” Dr. Naulleau concluded. “At EUV Tech, we believe in pushing the boundaries of what can be achieved in the production of EUV metrology equipment. We do this by not only achieving or exceeding product design specifications but also by providing world-class customer support to our business partners.”