SK Hynix Unveils World's Tallest '321-Layer' NAND Sample

238-step Productivity Improved by 59%
Mass Production Planned from First Half of 2025

SK Hynix has officially announced the development of NAND flash with over 300 layers for the first time in the memory semiconductor industry. They unveiled a sample of the 321-layer 4-dimensional (4D) NAND and announced mass production scheduled for 2025.

On the 8th (local time), SK Hynix presented the progress of developing the 321-layer 1-terabit (Tb) triple-level cell (TLC) 4D NAND and exhibited samples in the development stage at the 'Flash Memory Summit (FMS) 2023' held in Santa Clara, USA. FMS is the largest NAND industry conference held annually in Santa Clara. Last year, SK Hynix announced the development of the 238-layer 512-gigabit (Gb) TLC 4D NAND at this event.

An SK Hynix official said, "Based on the technological expertise accumulated through the highest-layer 238-layer NAND mass-produced since May, we are smoothly progressing with the development of the 321-layer NAND," adding, "SK Hynix will once again break through the stacking limit, opening the era of 300-layer NAND and leading the market."

The 321-layer 1Tb TLC NAND has 59% higher productivity compared to the previous generation (238-layer 512Gb). Because the cells that store data can be stacked to a higher number of layers, a single chip can implement a larger capacity. SK Hynix plans to enhance the completeness of the 321-layer NAND and begin mass production from the first half of 2025.

SK Hynix 321-layer 4D NAND image /
[Image courtesy of SK Hynix]

At the event, the company also introduced next-generation NAND solution products, including enterprise solid-state drives (eSSD) applying the PCIe (a serial interface standard supporting high-speed data input/output) 5th generation (Gen5) interface and Universal Flash Storage (UFS) 4.0. These products are optimized for the increasing demand for high-performance and high-capacity memory as the generative artificial intelligence (AI) market expands.

SK Hynix explained that these products boast industry-leading performance and can meet the demands of customers seeking high performance. They are also developing the next generation PCIe 6th generation and UFS 5.0, aiming to lead future industry technology trends based on these.

Choi Jung-dal, Vice President of SK Hynix (NAND Development), said in the keynote speech at the event, "We plan to solidify our NAND technology leadership by developing the 4D NAND 5th generation 321-layer product," adding, "We will lead innovation by proactively introducing high-performance, high-capacity NAND required in the AI era to the market."

This content was produced with the assistance of AI translation services.