Micron abandons 4F² DRAM research to focus on 3D DRAM

Micron has decided not to bring 4F² DRAM to market. Scott DeBoer, Micron's top technology executive, announced the decision during a technology webinar on October 21. While 4F² cells theoretically offer about a third smaller footprint than current 6F² layouts, DeBoer says the density advantage is "a bit of a myth" because capacitor spacing limits real-world density. He stated that 4F² can be built, but it would be more complex and expensive, and it faces scaling problems at leading-edge nodes.

This move places Micron apart from Samsung, SK hynix, and CXMT, all of whom are developing 4F² designs. CXMT claims its first 4F² server DDR5 RDIMM will be ready by the end of 2026, though no independent teardowns have confirmed this.

Micron plans to continue scaling 6F² technology. The 1-delta node is scheduled to ramp in Boise, Idaho, during the second half of 2027 and is expected to provide mid-20% bit-density gains. The company is also developing 3D DRAM on a parallel track, but it has not provided a timeline and says it will switch only when the economics make sense. Micron estimates that memory supply will remain tight through 2027 and 2028, partly because HBM and new vertical products use more wafer area per bit.