[News] YMTC Files Lawsuit Against Micron Alleging Patent Infringement Over 3D NAND Technology Battle

2023-11-13 Semiconductors editor

Mainland China’s 3D NAND flash memory manufacturer, Yangtze Memory Technologies Co. (YMTC), filed a lawsuit against the U.S. memory chip leader, Micron Technology, on November 9th in the Northern District Court of California. The lawsuit accuses Micron of infringing upon eight of YMTC’s U.S. patents related to 3D NAND technology.

According to ICsmart, the patents involved in this case from YMTC include US10,950,623 (3D NAND memory device and method of forming the same), US11,501,822 (Non-volatile storage device and control method), US10,658,378 (Through-array contact [TAC] for three-dimensional memory devices), and US10,937,806 (Through-array contact [TAC] for three-dimensional memory devices), US10,861,872 (Three-dimensional memory device and method for forming the same), US11,468,957 (Architecture and method for NAND memory operation), US11,600,342 (Method for reading three-dimensional flash memory), and US10,868,031 (Multiple-stack three-dimensional memory device and fabrication method  thereof).

In the complaint, YMTC alleges that Micron’s 128-layer, 176-layer, and other series of 3D NAND technology have violated eight patents owned by YMTC. Micron is accused of using YMTC’s patented technology without authorization to compete with YMTC, protecting market share and impeding YMTC’s interests, thereby inhibiting innovation.

In recent years, with the stacking of 3D NAND technology reaching 128 layers and even higher, the chip area occupied by peripheral CMOS circuits may exceed 50%. To address this issue, YMTC introduced its proprietary innovative Xtacking technology in 2018.

Established in July 2016 and headquartered in Wuhan, Hubei, YMTC is an IDM (Integrated Device Manufacturer) specializing in the design and manufacturing of 3D NAND flash memory. It also provides comprehensive memory solutions.

Under the shadow of the ongoing US-China tech rivalry, Micron Technology adopted a low-key approach at this year’s Import Expo in Shanghai. During a meeting with Micron’s CEO, Sanjay Mehrotra, Chinese Minister of Commerce Wang Wentao on November 1st welcomed Micron’s continued presence and expansion in the Chinese market, emphasizing the importance of adhering to Chinese laws and regulations for sustainable development. Mr. Mehrotra expressed the company’s willingness to further invest in China.

However, on May 21st this year, China’s Cyberspace Administration announced serious cybersecurity issues with Micron’s products sold in China. These products didn’t pass the review, leading Chinese operators to halt the purchase of Micron’s products. This indicates a potential ban on Micron’s products in the Chinese market.

In October 2022, the US imposed exprt restrictions on advanced chip manufacturing equipment, including placing 36 Chinese companies such as YMTC on an entity list.

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