GlobalFoundries Signs $2 Billion Deal to Make TSMC Interposers in New York

GlobalFoundries has agreed to manufacture silicon interposers for TSMC at its plant in Malta, N.Y., under a five-year agreement the company valued at $2 billion. The deal, announced Oct. 8, would give TSMC's CoWoS advanced-packaging business its first U.S. source of a component that sits under many of the largest AI accelerators.

An interposer is a thin slab of silicon wired with dense connections. In CoWoS packaging, the logic die and the stacks of high-bandwidth memory sit side by side on it, and the interposer carries signals between them far faster than a conventional circuit board could. As AI chips have grown larger and carried more memory, the interposer has grown with them, and so has the demand for the wafer capacity needed to make it.

Under the agreement, GlobalFoundries will provide manufacturing services to TSMC and add fabrication capacity at Malta. The company said it expects to establish "the first U.S.-based source of silicon interposers supporting advanced packaging technologies," including embedded deep-trench capacitors, which smooth the power delivered to the chips mounted above.

The timetable is the main constraint. GlobalFoundries said volume production is expected to begin ramping in the first half of 2028. The initial term runs five years, and the company described the deal as "a framework for future capacity expansion" as customer demand grows. It did not disclose how many wafers the agreement covers, how the $2 billion is structured or whether TSMC has committed to minimum purchases.

"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. He said the arrangement uses the company's "trusted U.S. manufacturing footprint" to create "a secure, scalable source of essential advanced-packaging elements."

For TSMC, the deal addresses a gap in its U.S. buildout. The company has been in volume production on its N4 process in Arizona since the fourth quarter of 2024, but its first Arizona advanced-packaging fab only entered the early stages of construction this year. An interposer made in New York would not by itself close that loop, since CoWoS assembly also requires packaging lines, but it moves one capacity-constrained input onshore.

For GlobalFoundries, the arrangement puts mature fabrication tools to work on a product tied to AI demand rather than to the smartphone, automotive and industrial markets that make up much of its business. Interposers do not require the most advanced transistors. They require large areas of reliably patterned silicon, which suits a fab with existing capacity.

Several questions will shape how much the deal matters. The first is economics: GlobalFoundries has not said what margin it expects on interposer work or how much new capital spending Malta will need. The second is scope: the release describes a manufacturing service to TSMC, not a direct relationship with the chip designers whose products will use the interposers. The third is timing: by the first half of 2028, the AI accelerators on the market will be at least one generation past today's, with larger packages that may need more interposer area per chip.

Investors will look for answers when GlobalFoundries next reports results. The company will also need to show that a 2028 ramp is on schedule, since the agreement's value depends on volumes that do not begin for more than a year.