--- title: "YMTC (长江存储) ships 294-layer NAND and licenses its hybrid-bonding patents to Samsung" date: 2026-10-21 category: Chips & Compute site: NeuroAI canonical: https://neuroai.site/a/na-chips-ytmc-xtacking-nand language: en --- # YMTC (长江存储) ships 294-layer NAND and licenses its hybrid-bonding patents to Samsung > China's leading 3D NAND maker turned a homemade architecture into a global patent asset, then crossed 294 layers while building a partly domestic equipment line. For years the playbook for Chinese memory makers was simple: catch up, then compete on price. Yangtze Memory Technologies, or YMTC (长江存储), is the first to flip that script — by licensing its own patents to the company that defined the category. The turn came not from a factory but from an idea. YMTC's Xtacking (晶栈) architecture, first shown in 2018, splits a 3D NAND chip into two wafers — one for the memory cells, one for the control logic — and bonds them with hybrid bonding. It sounds like an internal engineering detail. In 2025 it became a bargaining chip. ## How Xtacking rewrote the build order Traditional 3D NAND builds memory and logic on the same wafer, where the two fight for the same process. Xtacking separates them: the "storage warehouse" can be stacked as high as the process allows, while the "control highway" is built on the most advanced logic process available, then the two are bonded with micron-level precision. The payoff is higher density, faster I/O and a shorter development cycle. The timeline is unusually clean. YMTC designed China's first 3D NAND in 2017 and mass-produced its first Xtacking-based part in 2019. It moved through 64 layers, then 128, then a 232-layer third generation (the X3-9070) in 2022 at 2400 MT/s. In February 2025 it announced mass production of a 294-layer 3D NAND chip with sequential read/write speeds above 7000 MB/s and reported yields above 90% — a product built on Xtacking 4.0 with 232 active layers. By most accounts that put YMTC at parity with the leading global NAND makers on layer count. ## The Samsung license that surprised the industry The more striking event was not a product but a permission. Multiple reports, citing Korean media, say Samsung Electronics signed a 3D NAND hybrid-bonding patent license with YMTC and will use the Chinese company's bonding technology from its next-generation "V10" NAND onward. If accurate, it is a rare case of a Chinese memory patent being adopted by the global incumbent rather than the reverse. YMTC's patent estate supports the claim. Public figures put its global patent applications above 12,000, of which around 95% are invention patents, with more than 100 core hybrid-bonding patents. YMTC has also pursued patent litigation against Micron, signaling it intends to defend the architecture through the same international rules the incumbents use. ## A partly domestic equipment line The other 2025 milestone is less visible but strategically loaded. According to mainland industry reports, YMTC's first fully domestic-equipment production line entered trial production in the second half of 2025, with equipment localization reaching about 45%. Tools from domestic suppliers such as AMEC (中微公司) for etching were cited as part of the line. For a segment where lithography, deposition and metrology tools have been dominated by foreign vendors, a 45% domestic mix on a running line is a meaningful data point — even if the remaining 55% still depends on imported gear. YMTC's consumer brand, Zhiti (致态), has also gained share in China's retail SSD market, and its enterprise SSDs are reported in use by major Chinese cloud providers. The company's Wuhan base is described as running at roughly 100,000 wafers a month on its first phase, with expansion phases planned toward 300,000 wafers a month by 2028 in some projections. ## Why this matters beyond China NAND is a commodity where the winner is usually the one with the lowest cost per gigabyte at the highest layer count. YMTC crossing 294 layers means the "China can only do mature nodes" assumption no longer holds in memory. And the Samsung license shows that domestic substitution in China is not only about replacing imported parts at home — it can produce intellectual property that global leaders must pay to use. For global readers, the takeaway is a shift in the center of gravity. The NAND market's technology leadership used to be a closed conversation among Seoul, Tokyo and Boise. YMTC's hybrid-bonding patents are now part of that conversation. ## What readers can do now - Watch YMTC's layer-count and yield trajectory against Samsung and SK hynix quarterly — parity on 294 layers is the headline, but 3D NAND lead changes hands at the next node. - Track the equipment-localization rate: a rising percentage on running lines is a better signal of supply-chain autonomy than any single product launch. - If you buy SSDs, the Zhiti (致态) retail line is a tangible way to see YMTC silicon; compare specs and warranty rather than assuming "domestic" means inferior. ## Honest limitations The Samsung license is reported via Korean and Chinese media and has not been confirmed in a Samsung or YMTC press release in the sources reviewed; treat it as credible but unconfirmed by primary disclosure. The 45% equipment-localization figure and the 2028 capacity target come from mainland trade-media reports, not YMTC filings. YMTC is not publicly listed, so financial and capacity numbers are estimates. Patent counts are self-reported aggregates. None of this is investment advice. --- Published by NeuroAI (https://neuroai.site/) — https://neuroai.site/a/na-chips-ytmc-xtacking-nand Free to quote with attribution and a link to the original.