(Yicai) Nov. 13 -- Yangtze Memory Technology, China’s leading flash memory chipmaker, is suing Micron Technology in the United States for alleged patent infringement, saying the US chip giant illegally makes widespread use of eight of its patented innovations to head off competition and guard market share. 

YMTC filed the lawsuit against Micron and its subsidiary Micron Consumer Products Group on Nov. 9, seeking to end Micron's alleged widespread and unauthorized use of its patented technology, according to information released by the Northern District Court of California.

YMTC claims that Micron uses its patented technology for three-dimensional not-and flash, including those with 96-layer, 128-L, 176-L, and 232-L specifications, to fend off competition, protect its market share, and try to force the Chinese firm out of the 3D NAND flash market.

Chip sector analysis firm TechInsights concluded last November that YMTC’s innovative Xtacking 3.0 architecture put it in the lead of the global 3D NAND flash market, surpassing Micron, which the Chinese firm referenced in its indictment.

Since it was set up in 2016, Wuhan-based YMTC has invested heavily in research and development, filing nearly 4,000 patents in the memory space field.

YMTC mass-produced first-generation 32-L 3D NAND flash chips in 2018 and 64-L 256-gigabyte triple-level cell 3D NAND flash memory in 2019 and developed two 128-L flash memory products by skipping 96-L products in 2020.

In 3D NAND, memory cells are stacked vertically in multiple layers, enabling higher storage capacity and better performance. The vertical stacking is what distinguishes 3D NAND from the previous planar design, where cells were arranged horizontally in a single layer.

In the overall global NAND flash market, Samsung, Kioxia, SK Group, Western Digital, and Micron were the top five players in the second quarter of the year, with shares of 31.1 percent, 19.6 percent, 17.8 percent, 14.7 percent, and 13 percent, respectively, according to Trendforce. Other manufacturers only accounted for 3.8 percent of the total.

Apart from making technology breakthroughs, YMTC has been expanding capacity too. Price competition in the market intendified in the third quarter of last year due partly to YMTC’s increased shipments, according to Trendforce.

Last December, the United States included YMTC in its export control entity list after the country’s commerce department came out with new export controls on shipping chip manufacturing equipment to China, impacting progress in the Chinese NAND flash memory industry.

Editor: Futura Costaglione