René Raaijmakers
17 March

At ASML, system engineers and architects ensure that the right technical choices are made to create maximum value. Tom Castenmiller and Frank de Lange discuss systems engineering at the litho giant. This first article of two focuses on roadmapping and the process of arriving at a holistic system definition.

ASML’s latest annual report neatly defines the craft of developing, manufacturing and commercializing the world’s most advanced lithography systems: “We master this process by balancing our customers’ needs, product capabilities and technology solutions.” ASML is talking about systems engineering here. To this definition may be added that system engineers – at some companies, they call them “system architects” – do this to create value. Value for the customer. ASML’s systems thinkers are experts at translating this into maximum value for their own business.

The market success is compelling. At age 38, ASML now ranks in the top-40 in the daily changing list of the world’s most valuable companies, having a market capitalization of 240 billion euros (after peaking at 360 billion in 2021). Among the tech companies, it ranks 13th. And when it comes to complex hardware, only Apple, Tesla, Nvidia and Samsung are more valuable. ASML is worth more than chipmaker Intel and two and five times as much as IC equipment suppliers Applied Materials and KLA, respectively.

I mention this because systems engineering is all about making the right technical choices to create value. Ultimately, that translates into value for shareholders. You can also put it this way: ASML’s development organization is to the litho giant what oil wells are to Shell and BP.

To be clear: in an innovation machine like ASML, you’ll find many blood groups in research, development and engineering, but it’s the system engineers who ensure technical choices are made, together with an army of architects, with the goal of business success.


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Exotic technology

Fifteen years ago (remember that number), ASML was already able to substantiate the economic feasibility of its current state-of-the-art technology, extreme ultraviolet (EUV). EUV had its fans, for example at Intel, but for many material suppliers and equipment builders, this exotic technology was a bridge too far. It was, according to a large part of the chip industry, far too expensive and also unfeasible because of all the technical problems. Canon and Nikon made a well-considered decision not to choose this path – that too is systems engineering.

Technical problems did indeed arise at ASML. Even in large numbers. Here, ASML’s systems engineering approach played a big role in making the right decisions to get to solutions. Now that EUV is in its adolescence, the technology is helping to reduce the number of critical lithography masks in chip manufacturing by 40 percent. The number of process steps is nearly a third lower compared to multi-pattern lithography. The benefit for customers is as ASML predicted fifteen years ago: significantly fewer defects, lower costs and cycle time reductions.

In Veldhoven, they now expect the use of EUV to continue to grow and all advanced-node chipmakers to be employing it in production by 2024. Another new optical design with a larger numerical aperture is already set for the next few years, enabling 60 percent smaller features. In 2024, the first chipmakers will begin process development and mass fabrication is expected to start around 2025-2026.

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System engineer Frank de Lange: “ASML is less constrained by regulations because human lives aren’t directly at stake in the deployment of steppers and scanners.”


Tom Castenmiller and Frank de Lange, both senior managers of systems engineering at ASML, gave talks last year at the international organization for systems engineering Incose and the system architecture webinars of Bits&Chips. They also looked ahead, showed best practices and wondered whether it was time for a new era, say Systems Engineering 2.0.

I have no illusions that the systems engineering culture at ASML can be described in a few pages – I use the word “culture” here because people are the common denominator.

Also, while the systems engineering approach at ASML is inspiring, it doesn’t translate easily to other tech-driven organizations. De Lange, for example, points out a major advantage for his company: unlike in automotive, manned space flight or the medical industry, human lives are not directly at stake in the deployment of steppers and scanners. As a result, ASML is less constrained by regulations than, say, producers of medical equipment and car manufacturers, although litho scanners must, of course, be safe. It’s not the reason that ASML can develop at lightning speed, but fewer administrative hurdles help to meet deadlines.

Unlike satellite builders, ASML has the additional advantage that its first-generation machines don’t have to be flawless – chip manufacturers even placed barely-working EUV machines in their fabs. The reason was marketing: they could show the world that they were ahead of the curve.

Key drivers

Castenmiller and De Lange define their profession as “the task of ensuring that ASML’s engineers work on the right technical solutions and innovations.” What counts most is the result in the chip factory. For the past twenty years or so, it has no longer been just about imaging but about cooperating techniques to help customers achieve the highest possible yield. In addition to lithography, metrology and a whole suite of software tooling (computational lithography) now play a role. Castenmiller: “To deliver a node to the customer, we take into account the entire manufacturing system and incorporate ASML’s entire business landscape.”

System engineers generally use a list of points at which they must excel. These so-called key drivers are central to achieving business success. For ASML, they’re imaging and overlay (quality of the image), productivity (throughput and availability of machines in fabs), time to market (a day earlier in production saves a customer tens of millions), field upgrades (making existing machines more productive with new software or hardware), service and cost of goods. The latter are especially important in markets where ASML has competition, such as in older nodes (Canon and Nikon) and metrology (KLA, Applied Materials and Nikon).

Three processes

At ASML, the systems engineering department broadly watches over three processes. The establishment of longer-term plans and the process for a holistic system definition are covered in this article. The latter process is the interplay of imaging machines, measurement equipment and software to deliver the best results in the wafer fabs – also called the node solution process within ASML. The product generation process (PGP) will be covered in a follow-up article.

Every chip manufacturer can relate to ASML’s roadmap, but the holistic system definition – say, the specific customer solution – isn’t the same for every fab or IC manufacturer. Unlike the early years of the chip industry, different IC generations and different markets such as DRAM and NAND memories and microprocessors all have their own requirements. “Our products are tailored to opportunities in the market, but it’s also sometimes about special requests from customers. The point is, it all has to work together,” observes Castenmiller.

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“To deliver a node to the customer, we take into account the whole manufacturing system and include ASML’s whole business landscape,” says system engineer Tom Castenmiller.


In the roadmapping process, system engineers look three to ten years ahead. Because of the high investments in future systems and chip factories, they currently even aim for (here they are again) fifteen years. “Those investments are so high that you want visibility in time,” says Castenmiller. He notes that a crystal ball for a decade and a half is virtually impossible. “But we’re trying.”

To see the need for anticipation, we only have to look back to the recent past. Fifteen years ago, immersion lithography was just gaining steam, ten years back, ASML was delivering the first EUV machines for process development and five years ago, mass production with EUV was taking off.

In those fifteen years, ASML’s machine portfolio has changed significantly. It developed optical metrology for better overlay control and acquired HMI, a specialist in e-beam inspection technology. This made the Veldhoven-based company a serious player in the metrology market for ICs.

Crucial suppliers who couldn’t keep up with ASML’s pace of innovation were bought out of necessity. ASML is now also a supplier of lasers (Cymer) and precision glass components (Berliner Glas). It also decided to start making the pellicles (a thin membrane that shields the mask from dust) for EUV after customers indicated that they thought ASML’s original plan to do without them was a bad idea and no one else in the industry picked up the challenge.

In making these kinds of choices, the system engineers have rather intense conversations and cut corners. It’s a turbulent environment that involves a lot more than just aligning 11,000 engineers and ensuring that the R&D expenditure – 2.5 billion euros in 2022 – is of maximum benefit to the business.

Sixty pages

ASML’s roadmap is about sixty pages long. “It states what the requirements of customers are. So we need to find that out,” explains Castenmiller. “Sources are conferences, customers, but also projects we do with universities and R&D institutes. ASML agrees on the requirements twice a year with customers and internally in so-called litho solutions meetings.

Within ASML, various departments collaborate in drawing up the requirements. Corporate marketing, for example, studies the market impact, costs and potential value of new products. A special task is reserved for a group of technical experts with a great deal of knowledge of device technology. ASML recruits them from customers, where they often have years of experience with the effect of micro and nanostructures on ICs. Castenmiller: “They’re all seniors who have strong ties with customers and know everything about what’s involved and what’s relevant to get the components on chips working. Together with them, we study the devices that are coming, using every piece of information we can get.”

Strategic board

The systems engineering department defines what ASML needs to get done technically. “It’s about both current and future capabilities,” Castenmiller clarifies. “Because in our roadmap, both have to come together to see how quickly we can deliver.”

The second phase in roadmapping is the technology solution process. “This is a bottom-up process where we look at all kinds of new technologies that we can use.” This again involves numerous groups within ASML, including Research and various knowledge clusters within the Development & Engineering (D&E) organization.

The requirements and the technological solutions come together in the holistic solution definition process. There, systems engineering takes the lead and chooses the best solution for a node or customer-specific question. The results go to the strategic board, which decides what will and won’t be included in ASML’s product portfolio. If the idea is given the green light, it goes to the relevant business line, which then starts the product generation process. Castenmiller: “It doesn’t always work like that. It also happens that the business lines come up with new products, after which systems engineering looks at how they fit into the whole portfolio. Ultimately, it’s an iterative process in which everyone contributes to the overall node solution.”

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The first sheet of ASML’s roadmap, outlining the requirements for different markets (eg DRAM and microprocessors) and, in parallel, the planned machines (litho or metrology) with a description of the requirements for each node. Credit: ASML


Roadmapping is strategic for ASML and senior management decides on the final content. But what’s essential in the roadmapping process? Castenmiller points to technical leadership and a strong vision. “We draw up the semiconductor roadmap together with our customers. With them, we have very close ties, and creating such a long-term strategy is something we do together. We talk to everyone, but you have to have vision yourself,” says Castenmiller. “That’s where our CTO, Martin van den Brink, makes the difference.”

That leadership is evident in another way, too. To ensure the timely launch of its key technology litho, ASML has taken on the role of conductor – often by necessity. After all, you can ship a litho machine, but if the photoresist, metrology and infrastructure aren’t ready in time, chip manufacturers still can’t make chips. Everything has to be available at the same time. In the case of EUV, ASML had to come up with its own solutions to avoid showstoppers (EUV pellicles) or acquire companies to keep up the pace (EUV source at Cymer).


The holistic system definition process must ultimately arrive at a final solution that optimizes all ASML technology. “That means balancing specs, technology options and customer acceptance,” details Castenmiller. That’s where the device experts again play a crucial role because ASML needs to understand the effect of its machines in the IC manufacturing process. “We have to translate the information from the device expert team to the scanner designers, who talk a totally different language. In that translation, you have to look at what’s critical and what influence our products have on the specifications. For that translation, we have a separate group of engineers.”

But even after the translation from device to lithography, ASML isn’t there yet. “We also need to know and understand how the customer works and for that, we also have a dedicated group of system engineers, the field system engineers. They’re very close with customers and know exactly how they work and what can and can’t be successful with a specific customer.”

Then, slowly but surely, the final solution comes into view. With the technology roadmap options, systems engineering seeks a balance in hardware and software solutions with respect to lead time (the time it takes to ship the equipment), performance, complexity and cost for ASML and the customer. Castenmiller: “It’s a big puzzle. How much metrology do we need? How often do we need feedback? Do we perhaps need feedforward measurements? It all has to work together seamlessly and the end result has to be that the devices are optimized at the lowest cost.”

This is the first of two articles on systems engineering at ASML. The second part focuses on the product generation process. Main picture credit: ASML