SK hynix Starts Mass Production of World's First 321-High NAND

Industry's first 321-high NAND of 1Tb developed for supply in 1H25

"Three Plugs" process technology leads to technological breakthrough for stacking,improves speed,power efficiency

Company on track to becoming "Full Stack AI Memory Provider" with enhanced competitiveness in AI storage

SEOUL,South Korea,Nov. 21,2024 -- SK hynix Inc. (or "the company",www.skhynix.com) announced today that it has started mass production of the world's first triple level cell*-based 321-high 4D NAND Flash with 1Tb capacity.

SK hynix’s 321-high NAND

*NAND Flash products are categorized into single-,multi-,triple-,quadruple-,and penta-level cells,depending on the number of the information in the format of bit unit is stored in a cell. A bigger number of information stored means more data can be stored in the same space.

Following its previous record as the industry's first provider of the world's highest 238-layer NAND since June last year,SK hynix has become the world's first supplier of the NAND with more than 300 layers by finding a technological breakthrough for stacking. The company plans to provide the 321-high products to customers from the first half of next year.

Stacking more than 300 layers came into reality as the company successfully adopted the "3 plugs"** process technology. Known for an excellent production efficiency,the process 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.

With the adoption of the same development platform from the 238-high NAND on the 321-high product,the company could also improve the productivity by 59%,compared with the previous generation,by minimizing any impacts from a process switch.

** Plug: a vertical hole through layers of substrates aimed at creating cells at once

*** Low Stress: Preventing wafer warpage by changing the material into the plugs

The latest product comes with an improvement of 12% in data transfer speed and 13% in reading performance,compared with the previous generation. It also enhances data reading power efficiency by more than 10%.

SK hynix plans to steadily expand the use of the 321-high products by providing them to the nascent AI applications,which require low power and high performance.

Jungdal Choi,Head of NAND Development at SK hynix,said that the latest development brings the company a step closer to the leadership of the AI storage market represented by SSD for AI data centers and on-device AI. "SK hynix is on track to advancing to the Full Stack AI Memory Provider by adding a perfect portfolio in the ultra-high performance NAND space on top of the DRAM business led by HBM."

About SK hynix Inc.

SK hynix Inc.,headquartered in Korea,is the world's top tier semiconductor supplier offering Dynamic Random Access Memory chips ("DRAM"),flash memory chips ("NAND flash") and CMOS Image Sensors ("CIS") for a wide range of distinguished customers globally. The Company's shares are traded on the Korea Exchange,and the Global Depository shares are listed on the Luxemburg Stock Exchange. Further information about SK hynix is available atwww.skhynix.com,news.skhynix.com.

SK hynix’s 321-high NAND