SK Hynix announced on June 26 that it is ready for volume production of the world's first 128-layer one-terabyte (TB) 4D NAND flashes based on triple level cell (TLC) arrays.
The Korean chipmaker achieved the milestone in just eight months since it announced the world’s first 96-layer 512 Gb (gigabit) 4D flash in October last year.
The 128-layer NAND has the largest number of stacks in the chip industry, SK Hynix said. A single chip has more than 360 billion NAND cells, with each cell storing 3 bits.
SK Hynix has applied a set of new technologies as well as the 4D NAND technology to the new product. These technologies include ultra-uniform vertical etching technology, high-reliability multilayer thin-film cell formation technology, and ultra-fast low-power circuit design. SK Hynix's 4D NAND combines 3D charge trap flash (CTF) technology with periphery under cell (PUC) technology that stacks peripheral circuits under the cell.
In addition, this product has the industry's highest capacity of 1 TB as a triple-level cell (TLC) NAND flash. SK Hynix and other chipmakers developed a 1 TB quadruple-level cell (QLC) NAND flash with 96 layers. However, SK Hynix commercialized a 1 TB TLC NAND flash for the first time in the semiconductor industry.
In particular, the 128-layer 1 TB 4D NAND flash is expected to boost the chipmaker’s profitability through productivity improvement and cost reduction. Its bit productivity per wafer improved by 40 percent compared to a 96-layer 4D NAND flash. Also, its bit productivity is more than 15 percent higher than that of the same product without the application of periphery under cells (PUC) technology.
Process optimization using the same 4D platform reduced the number of processes by 5 percent. It can slash investment cost to upgrade a production line to produce 128-layer NAND flashes by 60 percent compared to the previous generation, SK Hynix says.
SK Hynix plans to sell 128-layer 4D NAND flashes beginning in the second half of this year and will roll out various solution products one after another. The company said its new product could be used in high-performance, low-power mobile solutions and enterprise solid state drives (SSDs).
Therefore, SK Hynix plans to develop next generation UFS 3.1 products in the first half of next year and supply them to flagship models including 5G models of smartphone makers. Their power consumption will drop by 20 percent, and the package thickness shrink to 1 mm. The company said smartphone makers would be able to make a 5G smartphone with a 2 TB storage capacity.
SK Hynix plans to launch a 2 TB SSD for consumers, a 16 TB SSD and a 32 TB NVMe SSD for cloud data centers next year. Next-generation 176-layer 4D NAND products are under development.
In the meantime, unlike the DRAM market that is dominated by three big producers, the NAND flash market is still shared by many competing companies. Yet the volume production of the new product may help SK Hynix form a three-runner race in the NAND flash market.
The NAND market outlook is more positive than that for the DRAM market. According to market researcher IHS Markets on June 26, the market for DRAMs will contract by an average of 2.9 percent annually from US$98.94 billion in 2018 to US$85.61 billion in 2023, while the NAND flash market will grow from US$60.19 billion to US$60.55 billion during the same period.
The DRAM market was set to become a three-runner race among Samsung Electronics, SK Hynix and Micron and the three enjoyed huge profits with operating profit to sales ratios of over 50 percent in operating profit last year. On the other hand, considering that no company has taken a big lead over other companies in the NAND flash market excluding Samsung Electronics, SK Hynix is likely to form a three-runner race similar to that of the DRAM market. As of the end of last year, Samsung Electronics ranked first with a market share of 38.5 percent, followed by Toshiba with 17.6 percent, Western Digital with 14.0 percent and SK Hynix with 11.0 percent, according to market researcher DRAMExchange.
As of the end of the first quarter, SK Hynix's sales breakdown showed 81 percent by DRAM sales and 17 percent by NAND sales. This means that SK Hynix has room to grow in the NAND flash market.