“Wants to exit tungsten, molybdenum moves in”: SK Hynix completes verification of 375-layer NAND, and three-tier U.S. stock beneficiary targets emerge

Author: Ada, Deep Tide TechFlow

According to industry research firm TrendForce, SK Hynix has completed 375-layer NAND design verification, with mass production planned to start at the end of 2026. The company will convert existing capacity to production. SK Hynix’s verification of 375-layer NAND has pushed a long-anticipated industry turning point to the forefront; nearly a quarter-century of tungsten used in chips is being replaced by molybdenum. The true winners of this material substitution are not storage factories but the upstream equipment and consumables suppliers.

Tungsten has supported nearly 25 years, but scaling is pushing its physical limits

It’s worth noting that Samsung was the first to introduce molybdenum in metal wiring, not SK Hynix. Samsung adopted molybdenum as early as its 286-layer ninth-generation NAND, which entered mass production in April 2024 and is now expanding molybdenum use to more process steps. SK Hynix’s current use of molybdenum on its product line is a first for the company, representing a catch-up move rather than an innovation.

This 375-layer product also has a history of revision. According to TheElec, SK Hynix originally targeted 400 layers, but due to the manufacturing complexity of stacking high layers, it was ultimately revised down to 375 layers. Even so, it remains a key leap in SK Hynix’s NAND roadmap, with 480-layer and 604-layer products believed to rely even more heavily on molybdenum.

While molybdenum replacing tungsten is not exclusive to storage, it marks an industry-wide turning point. Reports indicate that tungsten has been used as an interconnect metal in NAND, DRAM, and logic/foundry mid-process steps for nearly 25 years, but the demands of scaling are now breaking tungsten’s limits, making molybdenum the most promising alternative.

Molybdenum’s advantages go beyond low resistance. Unlike tungsten and copper, molybdenum does not require barrier layers to prevent diffusion, saving process steps and improving yield; its high melting point and oxidation resistance support direct deposition, making it more suitable for high aspect ratio structures like 3D NAND and GAA (Gate-All-Around) logic at advanced nodes. In other words, as layer counts increase and nodes shrink, tungsten becomes less feasible, and molybdenum’s potential for penetration grows. This is the foundation of the “selling shovels” logic: once substitution spreads, the beneficiaries are the tool and material providers.

Lam Research: the only manufacturer with mass-produced ALD molybdenum tools

The most direct and compelling story in this chain is Lam Research (LRCX). Its ALTUS Halo, launched in February 2025, is called by the company the industry’s first atomic layer deposition (ALD) tool to mass-produce molybdenum, with resistance improvements over traditional tungsten metallization exceeding 50% in most cases. Lam disclosed that early adoption has been implemented in high-capacity 3D NAND factories in Korea and Singapore, as well as advanced logic fabs. In Korea, this corresponds to Samsung and SK Hynix; in Singapore, to Micron.

Business resilience lies in process complexity. According to Zacks Research, Lam is currently the only supplier with ALD molybdenum tools in mass production, serving foundries and NAND customers. Although molybdenum deposition is slower and more complex, it allows Lam to expand the market for single-wafer metal deposition (SAM) at these advanced nodes by three times. Increased process difficulty actually creates incremental opportunities for equipment suppliers.

Entegris sells consumables; Micron is the only pure storage stock in the US stock market

Applied Materials (AMAT) is taking a different approach. In February, it launched the Spectral ALD system, which uses molybdenum to replace tungsten in transistor contacts, reducing resistance at this critical connection point between transistors and copper wiring networks. This system has already been adopted by several leading logic foundries. It’s important to distinguish that Lam’s molybdenum story focuses on NAND/DRAM wordlines, while AMAT’s molybdenum story centers on 2nm GAA logic contacts; their downstream applications differ, and they do not share the same benefit logic.

On the materials side, Entegris (ENTG) supplies molybdenum solid-state precursors, specifically molybdenum dichloride dioxide (MoO₂Cl₂), tailored for DRAM and 3D NAND, along with its ProE-Vap delivery system. The logic is that chain reactions from material switching will affect multiple process steps, including precursor selection, polishing pad design, slurry formulation, etching materials, and filtration. The process becomes more dispersed but spans multiple steps.

As for the storage manufacturers themselves, Samsung and SK Hynix are not listed on the US main stock exchanges. Micron (MU) is the only pure storage stock in the US, and it has gained a foothold in molybdenum. Lam cites Micron NAND VP Mark Kiehlbauch, stating that molybdenum metallization has enabled Micron to achieve industry-leading I/O bandwidth and storage capacity in its latest NAND products. However, Micron is a “user of molybdenum,” not a “beneficiary of molybdenum sales.” Its stock price is mainly driven by storage cycles and HBM, with molybdenum as a performance booster.

Beneficiaries? Molybdenum miners get a boost? Semiconductor demand is just a small part

In theory, molybdenum miners could be marginal beneficiaries of this story, with US stocks like Freeport-McMoRan (FCX), which produces molybdenum as a byproduct of copper mining. But the actual volume of molybdenum used in semiconductors is tiny. According to TheElec and industry estimates, Samsung purchased about 4 tons of molybdenum last year, around 10 tons this year; SK Hynix started with about 4 tons. The entire industry is expected to reach only about 80 tons by 2030. Compared to the global molybdenum market, primarily used in steel alloys with annual consumption in the hundreds of thousands of tons, semiconductor demand is negligible. Linking miner stocks to NAND narratives is an unjustified causal connection.

This also defines the true scope of the “tungsten retreat, molybdenum advance” story: SK Hynix’s 375-layer is just the starting point. The real reach spans NAND, DRAM, and materials across three major categories. In this metal replacement wave, the certainty lies more in tool and consumables sales. Storage factories using molybdenum are the beneficiaries in terms of performance, not valuation. The metal suppliers themselves are largely unaffected.

Disclaimer: This article does not constitute any investment advice.