ASML builds hybrid bonding tool, challenging Besi's lock on chip stacking

What's the deal? ASML is developing a die-to-wafer hybrid bonding tool, according to a SemiAnalysisDealroom has a profile for this one. Try Dealroom → report that reviewed 27 ASML bonding patent families filed between December 2022 and November 2024, mostly covering die-to-wafer designs. The move would push the Dutch lithography giant into chip stacking, where Netherlands-based rival Besi is currently the only supplier with die-to-wafer tools in volume production. ASML declined to comment.

What's the endgame? SemiAnalysis sees the tool as a natural extension of ASML's vertical integration. Its distinguishing feature: it runs on a track, with each die riding its own holder past process stations, a design meant to lift station utilisation and enable heterogeneous integration.

Why now? Hybrid bonding is central to advanced AI chips, and die-to-wafer bonding already runs in volume in logic. ASML could gain an edge in alignment accuracy and particle control — the two factors that set bonding yield — drawing on its lithography expertise. The report also notes ASML's deep ties to TSMC and Intel, Besi's main logic customers, including a joint photomask initiative announced in September 2026.

The threat to Besi: Logic accounts for most of Besi's hybrid bonding business today, concentrated at TSMC and Intel. Besi shares closed down 4.8% on October 16, 2026, following the report, and the company reports third-quarter results on October 22. SemiAnalysis also expects Besi's high-bandwidth memory prospects to weaken, with adoption of die-to-wafer bonding potentially slipping to 2029 or beyond.

What could go wrong? ASML has announced no product or timetable, and patent filings are not evidence of a production-ready tool. SemiAnalysis flags remaining hurdles around feed-forward metrology, the die-to-wafer contact, and keeping the process clean. Besi and Applied Materials have already launched their jointly developed Kinex system, so ASML would enter an active field.

The signal: Control of advanced chip packaging is becoming a prize in the AI era, and this is shaping up as a Dutch rivalry between two neighbours. If ASML's tool reaches qualification, its precision and customer relationships could reshape a market Besi has dominated — but that outcome remains far from certain.

Read more: newsletter.semianalysis.com, finance.yahoo.com, Reuters