SK hynix announces production of its 321-layer NAND flash — shipments will start in the first half of 2025

SK hynix has announced the mass production of the world’s first 321-layer NAND flash. According to the press release, the company will supply customers with its 321-high NAND flash featuring 1TB capacity starting in 1H 2025.

SK hynix’s 321-layer high NAND flash is built on a technology the company dubs the “3 plugs” process. This technology is purportedly known for its excellent production efficiency, and “…electrically connects three plugs through an optimized follow-up process after three times of plug processes are finished.” “For the process, SK hynix developed a low-stress material while introducing the technology that automatically corrects alignments among the plugs.”

SK hynix also uses the same development platform for its 321-layer NAND as its previous generation 238-layer flash, yielding a purported 59% improvement in 321-layer production. The move to 321 layers has purported improved data transfer speeds by 12% and read performance by 13% compared to the previous generation. Power efficiency has also been increased by more than 10%.

321-layer NAND flash is currently the highest-layer flash in the industry. Samsung is the closest so far, with its 280-layer NAND flash, but it is actively working on 300-layer and even 400-layer flash to compete with SK hynix. Micron, YMTC, and Kioxia are the furthest behind, with 232-layer and 218-layer architectures at the time of writing.

Samsung’s next-generation 300-layer NAND flash will purportedly be produced differently from SK hynix. It will use a “double-stack” technique, which involves placing one 3D NAND stack on a 300 mm wafer and building another stack of flash on top of the first one. SK hynix’s solution is purportedly more efficient and involves using three layers.