GlobalFoundries and TSMC have signed a five-year, $2 billion agreement under which GlobalFoundries will manufacture silicon interposers for TSMC's CoWoS advanced packaging technology at its Malta, New York fab, with volume production targeted for the first half of 2028.
The deal and its rationale
The pact creates a U.S.-based source for the custom silicon pieces that sit between logic chiplets and high-bandwidth memory stacks in AI and high-performance computing processors. By moving interposer fabrication to GlobalFoundries, TSMC customers gain a path to label their chips as fully made and packaged in America. "By providing manufacturing service using GF's trusted U.S. manufacturing footprint, we are creating a secure, scalable source of essential advanced-packaging elements that will help customers accelerate innovation and strengthen the semiconductor supply chain," Ed Kaste, GlobalFoundries' senior vice president of CMOS Business, said.
Technical hurdles remain
Interposers are not commodity parts. Each design reflects the specific number, size and placement of chiplets and memory stacks, along with power distribution networks, deep trench capacitors and signal integrity requirements. Large interposers can exceed lithographic reticle limits, requiring stitching, a process GlobalFoundries has not yet demonstrated at this scale. The companies have not disclosed how much capacity will be installed, only that the framework allows further expansion if demand warrants.
Capacity and IP questions
GlobalFoundries will act as a subcontractor producing multiple customer-specific designs, not a supplier of standardized components. That means its design rules, process flows and qualification procedures must mesh with TSMC's CoWoS packaging lines. Ownership and protection of intellectual property embedded in interposer layouts, some of which may originate with TSMC or its clients, have not been settled.
What this means for CoWoS supply
Interposer fabrication is only one step in CoWoS-S. Bonding logic and memory to the interposer, assembling onto organic substrates and final electrical testing remain in TSMC's hands. If GlobalFoundries delivers yield and throughput on schedule, the arrangement could relieve a bottleneck in TSMC's own advanced packaging capacity. If stitching or IP issues delay the ramp, the expected relief may arrive later than the first half of 2028.