SK hynix has announced its plan to begin mass production of its next-generation 375-layer 3D NAND flash memory by the end of 2026.
This decision isn't just a simple technology upgrade; it's a strategic move perfectly timed with the current market dynamics. The memory market, particularly for NAND flash used in SSDs, is experiencing a 'super-cycle' where prices are soaring. TrendForce projects NAND contract prices to increase by a staggering 170% in the first half of 2026 alone. This is largely fueled by the explosive growth in AI, which requires massive amounts of high-speed storage for data centers.
In such a market, the smartest strategy isn't necessarily to produce more silicon wafers, but to pack more data into each wafer. This is exactly what SK hynix is doing. By converting its existing M15 factory in Cheongju to produce the new 375-layer chips, the company boosts its bit productivity—the amount of data it can produce—without adding to the overall wafer supply. This maintains supply discipline across the industry, which helps keep prices firm.
So, what makes this 375-layer stack possible? The key is a material change. First, chipmakers have traditionally used tungsten for a crucial component called the word line. However, as layers get stacked higher and higher, tungsten's electrical resistance becomes a problem. The solution is Molybdenum (Mo), a material with lower resistance that allows for faster and more efficient operation in highly stacked chips. Second, the ecosystem is ready for this shift. Competitor Samsung is already using Molybdenum, and equipment suppliers like Lam Research and Tokyo Electron (TEL) have the necessary tools ready. This significantly lowers the risk for SK hynix.
This move is also closely tied to SK hynix's broader capital allocation strategy. The company is investing heavily in HBM, the high-performance memory essential for AI processors. With massive capital expenditures directed toward HBM and DRAM, converting existing NAND lines is a much more efficient and pragmatic approach than building expensive new factories. It's a calculated decision that balances technological advancement, market profitability, and resource management.
- NAND Flash: A type of non-volatile storage technology that does not require power to retain data. It's the memory found in SSDs, USB drives, and smartphones.
- Word Line: In 3D NAND, this is a horizontal conductive layer that acts as a gate to control the flow of electrons into a memory cell, essentially turning it on or off.
- Molybdenum (Mo): A metallic element with lower electrical resistance than tungsten, making it better suited for creating word lines in high-density, multi-layered NAND chips.