SEOUL, October 16 (AJP) - South Korean chipmakers claim they are in a different league from ChangXin Memory Technologies (CXMT), an Anhui-based Chinese memory maker little known outside the industry until its spectacular Shanghai stock-market debut in July.
They find themselves having to reassure questioning investors as the Chinese challenger pushes deeper into server DRAM, promising a product using a novel, denser memory-cell design called 4F² by year-end.
Song Jae-hyuk, the deadpan chief technology officer of Samsung’s chip division, was bombarded with questions about the feat at Samsung’s SEDEX 2026 booth in Seoul on Oct. 14.
He stoically acknowledged that Samsung, too, had been researching 4F² DRAM — a rare moment in which the Korean giant found itself answering questions about a Chinese underdog’s apparent head start.
Samsung Electronics shares plunged more than 10 percent and SK hynix lost 13 percent Thursday.
Are investors overreacting? For now, experts caution against mistaking a prototype for a commercial breakthrough. But they also acknowledge that China’s faster-than-expected ascent in a DRAM market long dominated by the two Korean chipmakers and Micron cannot be dismissed, particularly given its restricted access to advanced chipmaking equipment.
“If it is true that they have made a working die or a prototype, that alone is surprising,” Kim Deok-kee, a professor at Sejong University, said.
A functioning CXMT prototype would be a significant achievement if confirmed, he said, because the design represents a next-generation technology that established memory manufacturers are also pursuing.
Whether the design translates into a commercially competitive product remains an open question. Samsung and SK hynix are moving ahead with their own development, leaving the eventual pecking order far from settled.
The 4F² designation describes the area occupied by a memory cell. At the same minimum feature size, it represents a cell footprint one-third smaller than a 6F² layout, potentially allowing more memory cells within a given area.
Kim described the move toward smaller cells as a shared industry direction, rather than an entirely separate technological path pioneered by one company. The difficulty lies in fitting the components into a more compact structure while making the design work as a product.
A prototype can demonstrate that a concept functions. It does not, by itself, establish manufacturing yields — the proportion of usable chips produced — or show how consistently a supplier can deliver products meeting customer requirements.
Chinese manufacturers appear to be making an aggressive push into next-generation technologies, Kim said. Even so, announcing progress on a particular structure should not be treated as proof of leadership in finished products.
A source close to Samsung Electronics told AJP that the company was working toward mass production of DRAM using the design around 2028.
“We are working quietly, building a solid foundation,” the source said, adding that the products in which the technology would be used had not been finalized.
SK hynix separately confirmed to AJP that it was developing the technology.
The company had outlined its plans for 4F² DRAM as early as June 2025, when Chief Technology Officer Cha Sun-yong presented a long-term technology roadmap.
At the time, Cha identified 4F² vertical-gate technology and 3D DRAM as key areas of development to overcome the limitations of conventional memory scaling. SK hynix also said it was exploring wafer-bonding technology to improve cell efficiency and electrical performance.
Ahn Ki-hyun, an official at the Korea Semiconductor Industry Association, said the information available was insufficient to quantify the gap between CXMT and its Korean competitors.
“We have to test them under the same conditions to make a comparison,” Ahn told AJP.
Assessing CXMT’s competitive position based solely on its claims was nearly impossible without examining an actual product, he said. A meaningful comparison would require commercially available products that could be purchased and tested.
Customer adoption will provide another test of how far development progress translates into a competitive business.
Apple Chief Executive John Ternus told TIME in an interview published Thursday that memory shortages warranted considering all supply options. His comments came amid reports that Apple was testing Chinese-made memory, but did not confirm a commercial supply agreement.
Any evaluation of memory for consumer devices would also be separate from validation of CXMT’s proposed server products.
For CXMT, the next milestones are more concrete than a claim of progress: a product that can be independently assessed, manufactured consistently and accepted by customers.
For the Korean chipmakers, the challenge is to prove that being first to announce a new design is one thing — and delivering it reliably at scale is another.
Shares of Samsung Electronics and SK hynix staged a modest recovery Friday, closing up 3.6 percent and 1.2 percent, respectively.
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