Chinese chip maker Changxin Memory Technologies (CXMT) may have achieved another technological breakthrough amid tight U.S. trade restrictions, according to third-party analysis of a company paper delivered to an international conference. CXMT, China’s top dynamic random access memory (DRAM) developer, presented a paper to the 69th annual IEEE International Electron Devices Meeting (IEDM) in San Francisco, giving an indication of its design capabilities for gate-all-around (GAA) transistors – the most advanced transistor type for cutting-edge 3-nanometer grade chips. While CXMT has not provided a sample product, evidence that the Chinese company has an understanding of next-generation memory chip production has grabbed the attention of industry analysts, as the design of such chips typically involves technologies that are subject to U.S. export restrictions. Frederick Chen, a memory chip expert at Winbond Electronics, a Taiwan-based company, said the evidence of progress by CXMT is “impressive”, as it shows that the Chinese company is not far away from state-of-the-art research and products. “It’s significant because Samsung Electronics is trying to do the same,” Chen said.
In a statement to the South China Morning Post, CXMT said the paper “describes fundamental research related to DRAM structure and the feasibility of 4F2 design” and “it has nothing to do with CXMT’s current production processes”, suggesting that the design on paper is far from becoming a marketable product. “Any accusation that CXMT is violating U.S. sanctions or export controls is completely inaccurate,” the company’s export control experts said. “We firmly believe that the free flow of ideas that IEDM seeks to foster is essential for the industry’s innovation and development.”
CXMT said a few weeks ago that it had produced China’s first lower power Double Data Rate 5 (LPDDR5) DRAM chip, narrowing its gap with leading players such as South Korea’s Samsung and SK Hynix. Like other Chinese chip makers, CXMT is subject to broad U.S. export restrictions targeting the country, but the company has not been added to Washington’s Entity List like Wuhan-based rival Yangtze Memory Technologies Co. In an escalating tech war with China, the U.S. Bureau of Industry and Security in October set an even higher export bar on gear needed for key chip manufacturing, including lithography, etching, deposition, implant and cleaning, doubling down on its efforts to cap China’s chip-making capabilities.
In August 2022, the U.S. Commerce Department slapped export controls on four semiconductor-related technologies, including software specially designed for the development of integrated circuits (IC) with gate-all around transistor structure. These four technologies are also covered by the multilateral 1996 Wassenaar Arrangement on Export Controls for Conventional Arms and Dual-Use Goods and Technologies – of which China is not a member. Since the imposition of controls, analysts have said that electronic design automation (EDA) software constraints would affect China’s abilities to develop advanced 3-nm process design and fabrication. But China has proved its resilience, with Huawei Technologies surprising the world with its 5G-capable Mate 60 Pro smartphone – powered by a home-grown chip – earlier this year.
Founded in 2016, CXMT represents China’s best hope to catch up with South Korean memory chip giants Samsung Electronics and SK Hynix, and U.S.-based Micron Technology, in the global DRAM market. Dylan Patel, Chief Analyst at San Francisco-based semiconductor research firm SemiAnalysis, acknowledged the CXMT paper in a post on X, saying the company’s progress with the most advanced transistor architecture “breaks U.S. sanctions”. Patel highlighted an excerpt from the paper that states, “We have successfully fabricated the junction-less GAA with a hexagonal capacitor to realize a compact DRAM architecture.” CXMT has also been developing high-bandwidth memory (HBM) chips, a type of memory that has seen growing adoption for AI applications to hike data transfer speeds between the memory stack and processors, the South China Morning Post reports.
