GlobalFoundries Will Make TSMC's AI Chip Interposers in New York Under a $2 Billion, Five-Year Deal

Rivals rarely share customers, but the AI buildout is rewriting semiconductor etiquette. GlobalFoundries said on October 8 that it has signed a five-year, $2 billion manufacturing agreement with TSMC under which its fab in Malta, New York will produce silicon interposers for TSMC's CoWoS advanced packaging ecosystem. Volume production is expected to start ramping in the first half of 2028, and the deal includes a framework for further capacity expansion. GF shares rose as much as 7% on the news.

The part being outsourced is small but indispensable. An interposer is the thin slice of silicon that sits between an AI processor and the package substrate, wiring compute dies to high-bandwidth memory stacks through thousands of densely routed connections and through-silicon vias. Nearly every HBM-based AI accelerator relies on one. GF's versions will also embed deep trench capacitors, tiny energy reservoirs etched into the silicon that stabilize power delivery right next to the dies.

The reason two foundries that compete for accelerator customers are now working together is that AI's bottleneck has moved. Etching leading-edge logic is hard; packaging it at scale is harder, and the United States currently has no domestic source of interposers at all. Even chips fabricated in TSMC's Arizona fabs are still flown to Taiwan for final packaging. US-based CoWoS capacity is arriving in stages: GF's Malta interposers in the first half of 2028, Amkor's CoWoS-compatible packaging service in Arizona in 2028, and TSMC's own advanced packaging plants there in 2029.

"Advanced packaging is becoming increasingly critical to delivering the performance, power efficiency and scale required for next-generation AI systems," said Ed Kaste, senior vice president of GlobalFoundries' CMOS business, adding that GF aims to provide a secure, scalable source of essential advanced-packaging elements.

The deal slots into larger buildout plans on both sides. GlobalFoundries is in the middle of a roughly $16 billion US investment program, including an $11 billion-plus expansion that adds a 358,000-square-foot second fab at Malta and a packaging facility on the same campus. Its second-quarter revenue was $1.79 billion, up 9% sequentially, with its communications infrastructure and data center business growing 60% year over year. TSMC, meanwhile, said in July that it plans an incremental $100 billion for four additional Arizona facilities, bringing its total planned US investment to $265 billion across 12 sites.

What the announcement does not say matters too. Neither company disclosed how many interposers will be made, how large the Malta expansion will be, or which process node will be used, and the leading-edge processor dies that sit on these interposers remain outside the deal's scope. Those details will determine how much actual supply the agreement ultimately adds.

Still, the strategic read is straightforward. Advanced packaging has joined lithography as a chokepoint of the AI supply chain, and whoever controls it influences the tempo of accelerator shipments. With CoWoS capacity still tight, TSMC is effectively renting a rival's US real estate to ease the squeeze, and GlobalFoundries gains a marquee customer for capacity that might otherwise wait on the lower-power physical-AI market it is chasing with platforms like the FD-SOI roadmap it unveiled in Dresden this week.