South Korea charges 10, over alleged chip technology leak to China

South Korean prosecutors have taken action and accused 10 people on suspicion of leaking memory chip manufacturing technology to Chinese chipmaker ChangXin Memory Technologies CXMT.

According to authorities, this case helped pave the way for China's development of high-bandwidth memory HBM, a critical component for artificial intelligence computing.

The Seoul Central District Prosecutors' Office said on Tuesday, December 23, 2025, that five people, including a former Samsung Electronics executive and engineers, were charged and held in custody for violating South Korea's industrial technology protection law, while another five were charged but allowed out on bail.

Prosecutors said a former Samsung Electronics researcher who was leaving his job to join CXMT copied out hundreds of steps of proprietary DRAM manufacturing processes by hand, recording detailed process recipes covering equipment specifications, sequencing, and yield optimization.

They informed that handwritten notes were later used to reconstruct the manufacturing flow at CXMT.

Moreover, the investigation also found CXMT obtained additional DRAM technology from SK Hynix through a supplier, further accelerating its development.

Prosecutors said the leaked technology involved 10-nanometre DRAM processes that Samsung spent 1.6 trillion won developing, adding that Samsung was the only firm to have such commercialized technology at that time.

They also mentioned that CXMT subsequently adjusted and validated the stolen data to suit its own equipment, enabling it to achieve production of 10-nanometer DRAM in 2023, the first achievement by a Chinese firm.

While the illegal use of the technology laid the ground for CXMT's development of HBM, the losses for companies such as Samsung Electronics were estimated to amount to at least tens of trillions of won.

CXMT, which is eyeing a Shanghai listing at a valuation of $42 billion, last month unveiled its latest generation of DRAM, known as DDR5, in a direct challenge to its South Korean rivals.

Furthermore, Samsung Electronics, SK Hynix, and CXMT have not shared their verdict yet.