SK Hynix announces mass production of the world's highest 321-layer 1Tb TLC 4D NAND flash memory, plans to ship it in the first half of 2025

On November 21, SK Hynix just announced that it has started mass production of the world's highest 321-layer 1Tb (terabit, different from TB terabyte) TLC (Triple Level Cell) 4D NAND flash memory.

It is reported that the data transmission speed and reading performance of this 321-layer product are improved by 12% and 13% respectively compared with the previous generation, and the data reading energy efficiency is also improved by more than 10%.

SK Hynix said: "The company has been mass-producing the current highest previous generation 238-layer NAND flash memory products since June 2023 and supplying them to the market. This time, it has taken the lead in launching NAND flash memory with more than 300 layers, breaking the technological boundaries. It plans to provide customers with 321-layer products from the first half of next year to meet market demand."

It is reported that SK Hynix adopted the efficient "3-Plug" process technology during the product development process to overcome the stacking limitations.

IT Home learned that the technology is divided into three through-hole process flows, and then the three through-holes are electrically connected through optimized subsequent processes. In the process, low-deformation materials were developed and automatic alignment correction technology between through-holes was introduced.

In addition, SK Hynix’s technical team also applied the development platform of the previous generation 238-layer NAND flash memory to the 321-layer, thereby minimizing process changes and improving its production efficiency by 59% compared to the previous generation.