On 25 February 2026 ASML approved an annual report that says two things about the same machine: that ASML is the world’s only manufacturer of EUV lithography systems, and that the number of those systems it can build is limited by one supplier, Carl Zeiss SMT, in whose holding company it owns a 24.9% equity interest.
A chip rests on a handful of suppliers that almost nobody outside the trade can name, and the companies that depend on them write it down in their own filings: where a buyer states that a supplier is difficult to replace, the scarce skills, and the careers built on them, sit on the supplier’s side of that sentence.
This is the second piece of the CareerOn Industry Atlas on semiconductors. The first asked where the money is made in a chip. This one asks a narrower and more practical question: which companies could a chip plant not replace next year if they stopped delivering? It reads eight documents that the companies themselves published between October 2025 and June 2026: annual reports, a filing with the American securities regulator, a registration document filed with the French market authority, a results release and a product release. It names a company only where one of those documents says what that company supplies. Reputation is not evidence, and a list of famous names is not an answer.
One rule runs through every paragraph that follows. When a company describes its own position, we print its words, its verb and the date of the document, and we say that it is the company speaking. The words “only”, “sole”, “first” and “world leader” are claims made by the people who benefit from them. They may well be true. They are still claims, and a reader deserves to know which is which.
The only door
Lithography is the step that prints the pattern of a circuit onto a silicon wafer. For the finest patterns, the industry uses extreme ultraviolet light, known as EUV. A chip plant that wants to make the most advanced logic has to put an EUV scanner on its floor, and in its annual report for 2025 ASML describes the market for those scanners in one line: it is currently the world’s only manufacturer of EUV lithography systems.
That sentence is striking, but it is not the most important one in the report. A single maker of a machine is a familiar situation in heavy industry. What makes this case unusual is what ASML writes, in the same report, about its own ability to build. The report states that the number of lithography systems ASML is able to produce is limited by the production capacity of one of its key suppliers, Carl Zeiss SMT, which it calls its sole supplier of lenses, mirrors, illuminators, collectors and other critical optical components. It adds that it has an exclusive arrangement with Carl Zeiss SMT.
Read together, the two statements describe a door behind a door. Every advanced chip plant depends on one scanner maker. That scanner maker, by its own account, depends on one optics maker for the part that does the imaging. The ceiling on the world’s supply of the most advanced lithography is not set in Veldhoven alone. It is set by how many optical systems one supplier can deliver.
The door behind the door
A dependence described only by the buyer is half a story. The supplier’s own annual report gives the other half. The ZEISS Group annual report for the year ended 30 September 2025 describes ASML as its strategic partner and customer, and it states that the majority of all microchips worldwide are manufactured using lithography technologies from ASML. That is ZEISS speaking about its customer, not a market measurement, and we print it as such. The same report says that the lithography optics from ZEISS are at the heart of wafer scanners.
The two companies also describe the same financial tie in the same terms. ZEISS writes that ASML acquired 24.9% of the shares in Carl Zeiss SMT’s holding company. It records dividends of €320,556k1 payable to ASML as of its reporting date. ASML, in its own report, records a dividend of EUR 320.5 million received from that holding in 2025. Two documents, written by two companies in two countries under two fiscal calendars, print the same stake and the same payment. That agreement is worth more than either statement alone, because neither company had any reason to align its wording with the other.
The optics are not the end of the chain. A pattern is only as good as the mask it is copied from, and a mask with a defect prints the defect on every chip. Lasertec, a maker of inspection equipment, stated in a release dated 31 October 2025 that in 2019 it launched the world’s first actinic EUV patterned mask inspection system, meaning a system that inspects the mask with the same kind of light that will be used to print it. The word is “first”. It is not “only”, and nothing in the release claims that no one else now makes such a system. We print it as the company printed it.
Five links, five kinds of claim
Beneath the machines sit the materials. Shin-Etsu Chemical states in its annual report that it produces silicon wafers, the disc on which every chip is built, as well as photoresists, the light-sensitive coatings that receive the pattern, and photomask blanks, the plates from which masks are made. In the “At a Glance” chapter of its report for the year ended 31 March 2026, it ranks itself No.1 globally in semiconductor silicon and No.2 globally in photoresists and photomask blanks. The report gives no share and no basis for those rankings, so we print them as a ranking the company gives itself.
The last link in our chain is close to home for many CareerOn readers. Soitec, based in Bernin near Grenoble, describes itself in its results release of 27 May 2026 as a world leader in the design and manufacturing of innovative semiconductor materials. It makes engineered substrates, wafers built in layers so that the chips printed on them use less power or run faster. That is a self-description, and the table below labels it as one.
Five links of one chip, each claimed in its maker’s own words
| Link | Company | Its own words | Document |
|---|---|---|---|
| EUV lithography | ASML | the world’s only manufacturer | Annual Report 2025, 25 Feb 2026 |
| Optics for EUV | Carl Zeiss SMT | ASML’s sole supplier | ASML Annual Report 2025 |
| EUV mask inspection | Lasertec | the world’s first, in 2019 | release, 31 Oct 2025 |
| Wafers, photoresists, photomask blanks | Shin-Etsu Chemical | No.1 globally (wafers), No.2 globally (photoresists, blanks) | Annual Report 2026 |
| Engineered substrates | Soitec (Bernin) | a world leader | results, 27 May 2026 |
Sources 1 ASML Holding N.V. · 3 Lasertec · 4 Soitec · 6 Shin-Etsu Chemical
The table does something a ranking would not. It keeps the verb. ASML says “only”. ASML says Zeiss is its “sole” optics supplier. Lasertec says “first”. Shin-Etsu gives itself a place in a ranking without a basis. Soitec calls itself “a world leader”. These are five different kinds of claim, and flattening them into one list of “monopolies” would print a finding that none of the documents makes. The honest reading is narrower and more useful: at each of these steps, a named company says in a dated document that it holds a position few others share.
The buyer writes it down
A supplier’s description of itself is a sales document as much as a report. The stronger evidence comes from the other side of the contract, from the company that has to buy. STMicroelectronics, which runs a plant at Crolles near Grenoble, filed its annual report on Form 20-F with the American regulator on 26 February 2026. Among its risk factors it writes that, as it depends on a limited number of suppliers for materials, equipment and technology, it may experience supply disruptions. It then gives the reason in plain words: because such equipment and technology are complex, it is difficult to replace any one supplier or provider with another.
Nobody asked ST to write that sentence as marketing. A risk factor is written under legal obligation, to warn investors of what could go wrong, and lawyers remove what cannot be defended. When a chipmaker says in that section that a supplier is difficult to replace, it is stating a cost it bears.
The equipment maker and the chipmaker both write down the same dependence
| Company | What it wrote | Filing |
|---|---|---|
| ASML | The number of lithography systems we are able to produce is limited by the production capacity of one of our key suppliers, Carl Zeiss SMT | Annual Report 2025 |
| STMicroelectronics | it is difficult to replace any one supplier or provider with another | Form 20-F 2025, 26 Feb 2026 |
Sources 1 ASML Holding N.V. · 5 STMicroelectronics
Placed side by side, the two sentences in the exhibit describe the same dependence from both ends. ASML says its own output is capped by one optics supplier. ST says that its suppliers, as a group, are hard to substitute. Neither sentence names a way out. What they name, without meaning to, is where the bargaining power sits and where the knowledge that cannot be quickly copied is held.
How a buyer holds its supplier
A buyer that cannot replace a supplier has three choices: accept the risk, build a second source, or take a stake. ASML took the third. Its equity interest in Carl Zeiss SMT’s holding is 24.9%, and the dividend it received from that holding rose from EUR 225.4 million in 2024 to EUR 320.5 million in 2025.
ASML owns a quarter of its own bottleneck and was paid more by it in 2025
- 2024: EUR 225.4m dividend ASML received from Carl Zeiss SMT Holding, EUR million
- 2025: EUR 320.5m dividend ASML received from Carl Zeiss SMT Holding, EUR million
dividend ASML received from Carl Zeiss SMT Holding, EUR million
Source 1 ASML Holding N.V.
The exhibit matters for the thesis because it qualifies it. A chokepoint that the buyer co-owns is not the same thing as one the buyer cannot influence. ASML shares in the profit of its own bottleneck, sits close to its investment decisions, and has an exclusive arrangement for its output. Our reading, which the documents support but do not state, is that this is how the industry manages dependence it cannot remove: not by finding a second supplier, which the documents do not describe, but by binding the first one closer.
The counter-case
The strongest objection to our reading is that the words carrying it are the companies’ own, and that they describe the present, not a law of nature. “Only” is true until a second maker ships. “First” was true in 2019 and says nothing about today. A self-ranking with no stated basis cannot be checked by a reader, and we have not found a document that checks it for them.
The second objection is sharper, because it comes from a buyer in our own region. Soitec’s universal registration document for 2025-2026, filed with the French market authority on 10 June 2026, describes Shin-Etsu Handotai, known as SEH, as a strategic supplier of the bulk wafers Soitec starts from, in 200 mm and 300 mm, and at the same time as a competitor and a minority shareholder. It notes that Soitec has licensed its SOI patents to SEH. So even the Bernin maker that calls itself a world leader depends on a supplier that also competes with it.
The same document then does something the thesis must take seriously. It states that the “Limited number of suppliers” risk was revised downward to moderate, because the group can now rely on additional sources. That is a buyer writing, in a regulated filing, that a dependence it once rated higher has been reduced by adding suppliers. Difficult to replace is not the same as impossible to replace, and the documents show at least one company moving from the first toward something easier.
We therefore hold the thesis at the strength the documents allow. At EUV lithography and its optics, the documents describe a single maker and a single supplier, and a buyer that chose to own part of its supplier rather than find another. At wafers and materials, they describe strong positions that buyers can, with time and money, work around. The scarce skills are real in both cases, but they are scarcest where a second source does not yet exist.
What would change the reading
Three things would weaken this piece, and we will look for each of them when we next revise it. A dated document from another company stating that it ships EUV lithography systems would end ASML’s “only”. An ASML report stating a second source for its critical optics would end the door behind the door. And a buyer’s filing, from ST or another European chipmaker, stating that it has reduced its supplier risk as Soitec did would show that “difficult to replace” is a phase, not a structure.
One company is absent from this piece on purpose. Many readers will expect Air Liquide here, given its presence in the Isère valley. We did not find a dated document from Air Liquide that states what it supplies to which chip plant. A product page is not a dated document and a job advert is not evidence, so it stays out until such a document exists.
What this means for your career
The jobs that follow from this map are not the ones on a chip company’s front page. They sit where a buyer has written that a supplier cannot easily be replaced, and in the teams that keep a plant running around those suppliers. Three of them can be rehearsed on CareerOn today.
The first is the engineer who installs and qualifies the scanner itself. Every EUV machine that leaves Veldhoven has to be brought up inside a customer’s plant, tuned and proven before it prints a single production wafer. Our EUV lithography installation simulation puts you in that role, working through the qualification of a new tool against its process window.
The second sits on the materials side, where Soitec and its suppliers work. An engineered substrate has to be developed and then qualified by the customer who will build chips on it, and that qualification is where the dependence described in the counter-case is either tightened or loosened. Our SOI substrate simulation asks you to take a substrate through that development and customer qualification.
The third is the least visible and one of the most necessary. Masks, optics and wafers are only as good as the room they are handled in, and a single particle can undo the work of every supplier in the chain. Our cleanroom contamination control simulation asks you to find and remove the source of a contamination event before it reaches the product.
None of these simulations will tell you which company to join. What they can show you, in an afternoon, is whether you want to spend a career in the places this piece describes: at the step a buyer cannot replace, holding knowledge that cannot be copied quickly.