The board of SK hynix Inc., a major data center memory supplier, today approved the construction of two new fabs.

The initiative will cost 54 trillion South Korean won, or about $38.3 billion. It’s part of a broader $430 billion investment plan designed to expand SK hynix’s manufacturing capacity. That initiative, in turn, is itself a component of a multibillion-dollar push by the South Korean government to grow the local chip sector. The latter project also includes SK hynix rival Samsung Electronics Co.

SK hynix’s newly announced construction initiative will see it build a $25 billion fab called Yongin Y2. It’s the second of four chip factories that the company plans to build at the Yongin Semiconductor Cluster, a manufacturing campus about 20 miles south of Seoul. The first fab in the series is expected to open its doors next February.

SK hynix plans to break ground on Yongin Y2 in July 2027. The facility’s first cleanroom, a factory section that contains chipmaking equipment, is scheduled to come online in June 2029. The factory will have 279 acres of floor space once construction is complete. 

Yongin Y2 will be dedicated solely to DRAM manufacturing. SK hynix will use the fab to make, among other products, HBM memory. That’s the high-speed RAM used by graphics cards to store artificial intelligence models and their data.

SK hynix is the world’s largest HBM producer. An HBM chip comprises multiple layers of RAM stacked atop one another, an arrangement that makes it possible to move data to and from the attached AI chip at high speed. 

The company debuted its most advanced HBM device, a 12-layer chip, last September. It’s based on a new version of the technology called HBM4. The standard provides more than twice the bandwidth of the memory that  powers today’s graphics cards.

The second new fab that SK hynix plans to open will make NAND flash. It will be built on a campus that already hosts three of the company’s chip factories. According to SK hynix, the existing power and water infrastructure on the site will speed up construction. The company expects to open the fab’s first cleanroom in December 2028.

Earlier this year, SK hynix and partner Sandisk introduced a new NAND flash technology called HBF. It stacks NAND flash circuits atop one another in a manner similar to HBM. According to the companies, the technology can match the performance of HBM while providing up to 16 times more capacity.

Samsung, SK hynix’s top rival in the memory market, is also developing vertical memory technologies.

Today, NAND and HBM modules are placed next to the logic circuits of the host chip. On Wednesday, Samsung debuted two new technologies that make it possible to stack NAND and HBM memory directly atop logic circuits. That arrangement shortens the distance between components, which enables data to travel faster between them. The result is an increase in processing speeds.

Samsung estimates that its stackable HBM technology will be eight times faster than HBM5, an upcoming version of HBM set to launch towards the end of the decade. The company also expects a tenfold increase in memory density, a measure of a RAM chip’s capacity. Samsung will give customers the option to further optimize the technology by adding in custom interconnect components.

Image: SK hynix