The era of 200-layer NAND is dawning. As competition among NAND flash semiconductor companies intensifies, the competition for the highest layer of vertically stacking cells is taking place in the 200-layer range.

SK Hynix has succeeded in developing the highest-level 238-layer NAND. On the 3rd, SK Hynix released samples of the 238-layer 512-gigabit TLC (Triple Level Cell) 4D NAND flash to customers and announced plans to begin mass production in the first half of next year.

SK Hynix has proven its technological prowess by successfully implementing 238 layers, which is higher than the world's first 232-layer NAND flash from Micron in the US last month.

SK Hynix unveiled a new product at the 'Flash Memory Summit (FMS) 2022', the world's largest NAND flash industry conference that opened in Santa Clara, USA on this day. In the event keynote speech, Choi Jeong-dal, SK Hynix Vice President in charge of NAND development, emphasized, “SK Hynix has secured global top-class competitiveness in terms of cost, performance, and quality through the development of 238-layer 4D NAND technology,” and “We will continue to innovate to overcome technological limitations.”

In this year’s event keynote, SK Hynix made a joint presentation with its NAND solutions subsidiary, Solidigm.

SK Hynix has been introducing 4D products that go beyond the existing 3D since the 96-layer NAND developed in 2018. To create 4D, where chips are implemented in a four-dimensional structure, the company’s engineers applied CTF (Charge Trap Flash) and PUC (Peri Under Cell) technologies. 4D has the advantage of increasing production efficiency while reducing the cell area per unit compared to 3D.

Not only does the 238-layer process have a higher number of layers, but it is also the world’s smallest, which increases productivity by 34% compared to the previous generation of 176 layers. This is because more chips with larger capacities per unit area are produced per wafer than before.

In addition, the 238-stage data transfer speed has increased by 50% compared to the previous generation to 2.4Gb per second. In addition, the energy usage of the chip when reading data has decreased by 21%, so it is expected to meet the 'power-to-performance' trend by reducing power consumption.

SK Hynix announced that it plans to first supply the 238-layer product that goes into cSSD (client SSD), a PC storage device, and then expand the product's utilization range to high-capacity SSDs for smartphones and servers. Next year, a 1Tb product with twice the capacity of the current 512Gb will also be introduced.

SK Hynix said, “We have succeeded in developing next-generation technology just 1 year and 7 months after developing 176-layer NAND in December 2020,” adding, “This 238-layer NAND is particularly significant in that it is the world’s smallest product while being the highest layer.”