ChangXin Memory Technologies (CXMT) had to delay mass production of its DDR5 memory devices in a bid to improve quality to late 2025, reports Digitimes. However, it looks like the quality of the company's DDR5 ICs is now on par with that of Nanya, according to the same report. The combination of improved yields, quality, and CXMT's expanding production capacity can make not only smaller Taiwan-based vendors, but also global players worry about CXMT's impact on the market.
Quality and yields plague CXMT's DDR5
In an unexpected turn of events, CXMT reportedly began to produce its DDR5 memory late last year, which made the industry worry that the China-based DRAM maker planned to flood the market with cheap DDR5 ICs. Later on, it was revealed that CXMT was using an outdated (presumably its 4th Generation DRAM node) process technology to make its 16 GB DDR5 devices, which is why they were 40% larger compared to 16 GB DDR5 ICs produced by Samsung. This meant that CXMT's DDR5 DRAMs are significantly costlier to build compared to DDR5 chips by Samsung, which makes flooding the market with such devices particularly hard and unprofitable.
But costs were not the only reported issues with CXMT's DDR5 chips. Early testing of CXMT's DDR5 samples in early 2025 allegedly exposed stability issues at around 60°C (a common temperature for DDR5 memory modules in tightly packed systems) and also problems with operation at sub-zero temperatures. These issues prevented modules based on CXMT's DDR5 ICs from meeting reliability standards. As a result, CXMT reportedly had to change the design of their DDR5 devices to a degree that it had to make new photomasks (a costly process), which reportedly solved problems with operating at high or low temperatures.
As a result, CXMT had to delay mass production of its DDR5 memory. Insiders initially projected volume production to start around May or June 2025, but by July, there was no evidence of volume shipments, reports DigiTimes. As it turns out, despite advancements with thermals, yield rates on CXMT's production line are still relatively low, hovering just above 50%, which is unacceptable for commodity DRAM. Digitimes supply chain sources suggest that more refinement and operational experience will be required before CXMT can reach yields competitive with the industry average, which will further delay mass production. For now, the company is targeting large-scale DDR manufacturing by the end of 2025.
Improving quality
Recent tests of CXMT's DDR5 modules indicate a significant leap in quality and performance that are now said to be nearly on par with Taiwan's Nanya Technology, according to DigiTimes. If these products are validated by leading PC makers or module products, their validation will suggest that CXMT is closing the gap with established DRAM suppliers. Of course, these parts have not yet entered high-volume production due to yield issues, so for now, CXMT can hardly be considered a competitor on the DDR5 market.
Western companies may withdraw maintenance
While CXMT has reportedly refined the quality of its DDR5 ICs and is on track to improve production yield, the company still faces major challenges.
First up, CXMT's 16 GB DDR5 is costlier to make than similar chips from other companies as CXMT's G4 fabrication technology has a feature size of around 16nm, according to TechInsights, which corresponds to Samsung's 3rd Generation 10nm-class node the company introduced in early 2021.
Secondly, because CXMT's G4 manufacturing process has a feature size of 16nm, makers of wafer fab equipment can no longer maintain tools used to build such memory chips in China as the U.S. export rules imposed in 2022 prohibit shipments or maintenance of wafer equipment in China that can be used or are used to make DRAMs on nodes more advanced than 18nm. If CXMT's suppliers (which include American, European, and Japanese companies) can no longer support the company's tools or supply spare parts or raw materials to the DRAM maker, it will make it particularly hard for the company to improve yields or mass produce its DDR5 memory.
CXMT keeps expanding capacity, for now
Unlike American, Japanese, or Taiwanese DRAM makers that rely on themselves and have to maintain profitability in order to invest in new production nodes and tools, CXMT is a state-funded entity designed to improve China's self-sufficiency in the production of semiconductors. This ability to use national resources gives CXMT a strategic advantage over its rivals and enables it to keep expanding production capacities even amid quality and yield issues.
Morgan Stanley estimated that CXMT's production capacity in 2024 was around 170,000 300-mm wafer starts per month (WSPM), and the plan for this year is to increase output to a whopping 240,000 300-mm WSPM per month. Digitimes reports even more impressive numbers, claiming 280,000 wafers per month by the end of 2025, with room to grow to 300,000. For now, CXMT scales both output, quality, and yields, which is why established global DRAM vendors may face increasing pressure eventually. But there is a catch.
CXMT's production capacity expansion heavily depends on tools made outside of China, as for now localization of tools at CXMT's fabs is around 20%, according to Morgan Stanley numbers cited by @Jukanlosreve. That said, if American, European, and Japanese companies cease to supply production tools to CXMT and cease maintenance of existing fab equipment, the company will be unable to expand its capacities at a rapid pace going forward. Furthermore, even improving quality and yields could be jeopardized without tools from outside of China.
In theory, CXMT can switch to fab equipment made in the People's Republic, but it will take years for the company to adopt these tools, tailor its process technologies for them, and ramp up mass production. Nonetheless, with nearly unlimited funds from China's government, CXMT remains a formidable prospective competitor for global DRAM makers.
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