Starting this month, SK hynix will begin in earnest to expand output of cutting-edge DRAM at its new M15X plant in Cheongju. There is speculation that M15X will become a key base for SK hynix to increase production of high-bandwidth memory (HBM) through next year. Although overall production volume is still smaller than at the company's plants in Wuxi, China, and Icheon, Korea, the plan is to deploy a large number of advanced process tools and move up the ramp-up (full-scale operation) schedule to maximize revenue during the supercycle.
According to the industry on the 10th, SK hynix's M15X plant will gradually increase monthly wafer (semiconductor wafer) input from an average of 10,000 units starting this month and expand to a maximum average of 80,000 units per month next year. In particular, judging by the pace of equipment move-in and setup this year, the line is expected to process an average of 30,000 to as many as 50,000 units per month within the year. The schedule has been moved up by about two months from the original plan. Most of the DRAM produced at M15X will be allocated to high-revenue products, including 6th-generation HBM (HBM4), with some used for server-grade high-performance DRAM.
M15X is a new DRAM production base that SK hynix expanded from the existing M15 plant with an investment of about 20 trillion won. Until the first fab in the Yongin semiconductor cluster is completed in 2027, M15X will respond to demand for next-generation HBM. The actual start of operations at the Yongin semiconductor cluster fab remains unclear; the industry expects operations next year, but inside and outside SK hynix, the view is that 2028 or later is likely due to issues with local governments and infrastructure. Accordingly, given SK hynix's limits on expanding production facilities, M15X will be the only bulwark for increasing DRAM production capacity until the Yongin cluster goes into operation.
M15X is a state-of-the-art line with a large deployment of extreme ultraviolet (EUV) lithography tools needed for mass-producing cutting-edge DRAM. The industry says about 12 trillion won worth of EUV equipment has been installed at M15X. The DRAM chiefly produced on this line, 10-nanometer-class 5th-generation (1b), is expected to help increase the share of high-performance DRAM for servers, PCs, and mobile devices, including HBM.
If the M15X plant enters full operation, SK hynix's DRAM output is expected to increase 10% to 15% in terms of wafer volume. However, because it is a line specialized for advanced processes, the consensus is that it will contribute more in terms of HBM supply capacity, sales mix, and profitability. SK hynix earlier emphasized M15X as an HBM-optimized base during its earnings conference call, and considering SK Group Chairman Chey Tae-won's explanation that HBM consumes far more wafers than general DRAM, most of the volume is likely to be used to strengthen HBM dominance.
It is also significant that SK hynix's DRAM production synergy, which revolves around Wuxi in China and Icheon, is expanding to Cheongju. The M15X plant is located directly adjacent to the existing M15 plant, and M15 is expanding investment in through-silicon via (TSV) equipment, which is said to be advantageous for optimizing HBM production. TSV is a technology that implements vertical electrical connections based on a silicon interposer and is essential for producing memory such as HBM. Centered on M15 and M15X, the Cheongju fab is expected to emerge as one of the HBM hubs, aligning TSV back-end processes with future Cheongju packaging investments.
A source familiar with SK hynix said, "M15X is an expansion card that can boost SK hynix's total DRAM wafer production capacity by close to 20%, but the more fundamental meaning lies not in the number itself but in being a plant that resolves the bottleneck for advanced DRAM for HBM," adding, "The goal is not only the simple effect of increased production, but also to fill the gap before the Yongin plant goes into operation and respond quickly to the battle for HBM market dominance with competitors."