Micron Technology said it will not commercialize 4F-square, or 4F², the next-generation DRAM design that rivals Samsung Electronics and SK hynix are developing, concluding that the gains in performance do not justify the development cost. The company said it will focus instead on three-dimensional DRAM.
Scott DeBoer, Micron's president and chief technology and products officer, said on a conference call on the 21st that Micron invented 4F² technology and had studied the design for 20 years before deciding against commercializing it, according to Yahoo Finance and other foreign media.
4F² refers to the area occupied by a memory cell. The design allows higher density than the 6F² structure used in DRAM now in mass production. But DeBoer said that while 4F² DRAM can be manufactured, the cost is too high and the process becomes excessively complex. He called the claim that 4F² holds a density advantage over 6F² "somewhat of a myth," adding that "there are fundamental limits to 4F² scaling. It will ultimately lead to adopting 3D DRAM instead of 4F²."
In line with that judgment, Micron introduced a family of stacked memory products it calls vertical high-bandwidth memory. Whereas conventional HBM sits alongside the processor, vertical HBM places the memory directly on top of it. Micron also laid out a roadmap under which it will mass-produce next-generation 1-delta DRAM in the second half of 2027, following its current mainstay 1-gamma, and then apply wafer bonding technology to 1-epsilon.
The move appears to be an attempt by Micron, the world's third-largest DRAM maker behind Samsung Electronics and SK hynix, to take the lead in next-generation 3D DRAM and shake up the market. Micron shares have fallen nearly 40% from their peak of $1,250 in June.
Micron is also facing pushback from unions demanding a share of profits. The Taichung union, one of Micron's two main unions in Taiwan, reached an agreement with management the previous day, but the union at the Taoyuan plant in northern Taiwan began a one-day strike at 9 a.m. on the 22nd, according to Taiwan's Central News Agency and other outlets. The Taoyuan plant accounts for about 22% of Micron's total DRAM production capacity. At the Taichung plant, some union members oppose the agreement that was reached.