China Memory Maker YMTC Sues Micron Over Patent Infringement

US-sanctioned Chinese memory maker Yangtze Memory Technologies Co (YMTC) has sued US chip maker Micron for patent infringement, alleging the company infringed eight of its patents in a bid to protect market share.

The company filed a civil lawsuit against Micron and subsidiary Micron Consumer Products Group on 9 November in the US District Court for the Northern District of California.

It said Micron, the US’ largest and only remaining memory maker, was “freeriding” on eight of YMTC’s patented inventions.

“YMTC recently filed a lawsuit in the US District Court for the Northern District of California against Micron Technology for infringement of our company’s patents related to the design, manufacture, and operation of 3D NAND technology,” the company said in a statement.

Tech tensions

“We are confident that this matter will be resolved swiftly.”

The products named in the lawsuit include YMTC’s NAND flash memory chips with 96, 128, 176 and 232 layers.

The lawsuit comes against a background of escalating tensions between the US and China that has directly affected both YMTC and Micron.

YMTC was founded only seven years ago but has grown quickly to gain a significant share in the global NAND flash memory market estimated at 6 percent in 2022, according to data presented by Chinese semiconductor expert Ni Guangnan at a forum in August.

Memory competition

Ni said YMTC’s share was expected to fall to 5.7 percent this year due to US sanctions, while he estimated Micron’s share would drop to 10.9 percent from 11.3 percent.

In April Chinese regulators launched an investigation into Micron and banned its products from critical infrastructure in a move widely seen as retaliation for the US adding YMTC to the Entity List blacklist in December 2022.

Escalating US sanctions imposed broadly on Chinese companies in October 2022 and October 2023, as well as on individual companies such as YMTC and Huawei, have forced Chinese tech firms to find new suppliers to replace US parts and technologies.

In spite of the US moves, however, Huawei earlier this year debuted the Mate 60 smartphone with a 7-nanometre chip made by Shanghai-based Semiconductor Manufacturing International Corp (SMIC), according to a teardown by TechInsights.

Chip advances

Last month TechInsights said YMTC had begun making what it described as the “world’s most advanced” 3D NAND memory chip, found in a solid-state drive launched quietly in July.

NAND flash is used in products such as USB memory sticks, memory cards and solid-state main computer storage drives.

Micron and YMTC both compete against world-class memory giants including Samsung Electronics, SK Hynix and Kioxa, with Samsung leading the memory market with an estimated 37 percent this year