Samsung's Giheung HBM expansion could cost 30 trillion won

By Amara Osei

Samsung Electronics (005930.KS) will build a 2nm/4nm foundry and advanced-packaging hub at Giheung for high-bandwidth memory (HBM), with fab investment estimated at 25 trillion won ($17.1 billion) and overall costs potentially reaching 30 trillion won.

The industry expects Samsung's HBM supply, measured in bits, to grow at a 52% average annual rate over the three years through 2028.

What will Samsung build at Giheung?

Samsung has begun an overhaul of its Giheung campus in Yongin, Gyeonggi Province. The site will combine foundry production of key HBM components with advanced packaging.

Samsung named the task force overseeing the overhaul Kairos, after the Greek god of opportunity. The company chose the name to reflect its expectations for the project.

Industry sources said on the 4th that demolition finished last month on the site of the former Samsung Advanced Institute of Technology's SR5 building and the former engineering college's CDI building.

The new complex will contain:

• A Kairos mixed-use building
• A green building
• A substation

Samsung E&A will handle engineering, procurement and construction.

The first step in Project Kairos is the Kairos fab, based on 2nm and 4nm processes, on the cleared institute and college site. Like Samsung's new Pyeongtaek plant, Samsung will develop the Kairos fab in four production phases.

Takeaway: The first construction step gives Giheung a defined role in leading-edge foundry and HBM-related manufacturing.

Why does HBM demand drive the project?

Rising HBM demand, driven by rapid growth in the AI data-center market, underpins the decision to build on idle land at Giheung. Large technology-company orders are accumulating as suppliers expand output.

Samsung currently produces core dies for HBM4, its latest sixth-generation memory product, at its Hwaseong and Pyeongtaek campuses. Only some lines at those campuses produce the 4nm base dies.

Once the Giheung fab operates, Samsung expects base-die capacity to rise in step with core-die output at Hwaseong and Pyeongtaek. The project therefore connects new leading-edge wafer capacity with the memory supply chain.

Takeaway: The new fab links base-die capacity to forecast growth in Samsung's HBM supply.

Which existing fabs will the project change?

Giheung opened in 1983, when Samsung's semiconductor business began. Its two flagship fabs use different wafer sizes and product sets.

• Line 6 uses 8-inch (200-millimeter) wafers.
• Line S1 uses 12-inch (300-millimeter) wafers.

Line 6 consolidates capacity from three former fabs, Lines 6, 7 and 8. It mainly makes legacy chips, including image sensors, display drivers and power semiconductors.

Samsung dedicates Line S1 to the System LSI Business, which makes mobile application processors and automotive systems-on-chip.

Although Giheung mainly operates mature processes ranging from tens to hundreds of nanometers, Project Kairos inserts leading-edge capacity through the new fab. The task force also plans to convert part of Line 6 into an advanced-packaging facility.

Advanced packaging is a back-end process that stacks chips vertically or links them side by side to assemble a larger chip. The process is essential for producing finished HBM products.

Takeaway: The project adds leading-edge foundry and packaging work alongside the campus's mature-node operations.

How does the node roadmap map to HBM?

Samsung began mass-producing HBM4 this year. The sixth-generation product uses 4nm base dies.

HBM4E, the seventh generation, is slated for mass production next year and will also use 4nm base dies. Samsung expects HBM5, the eighth generation, to enter mass production next year as well.

Samsung is likely to apply a finer 2nm process to HBM5 base dies. Building a 2nm line prepares the company for that product and extends its foundry roadmap beyond the 4nm nodes used for HBM4 and HBM4E.

Takeaway: The roadmap assigns 4nm base dies to HBM4 and HBM4E and a 2nm process to HBM5.

How much will the project cost?

Investment in the Kairos fab is estimated at about 25 trillion won ($17.1 billion). According to people familiar with the matter, Samsung has prepared purchase quotations for dozens of extreme ultraviolet lithography machines worth 8 trillion to 10 trillion won.

EUV lithography provides the key equipment for leading-edge processes. Adding cleanroom construction and non-lithography manufacturing equipment pushes the reported total above 20 trillion won.

Observers put the total at as much as 30 trillion won when they include the Line 6 advanced-packaging conversion. That range makes EUV procurement, cleanroom construction and the packaging retrofit the main cost variables.

Takeaway: The investment links a 25 trillion won fab to a Giheung project that could reach 30 trillion won.