[News Terms] What Does '236-Dan NAND' Mean?

Samsung Electronics unveiled the 8th generation V (Vertical) 236-layer NAND flash on the 7th / Photo by Samsung Electronics official website capture

Samsung Electronics announced on the 7th that it has started mass production of 236-layer NAND flash, which is currently the industry's highest-level commercial data storage device. NAND, a type of memory semiconductor, is measured primarily by the number of layers, which is considered the most important performance indicator.

On this day, Samsung began production of the '8th generation V-NAND.' Compared to the previous generation (176 layers), the 236-layer NAND offers a much higher number of layers, with a capacity reaching 1 terabyte (Tb). Samsung is currently the only memory semiconductor manufacturer to have succeeded in mass-producing 236-layer NAND. U.S.-based Micron is mass-producing 232-layer NAND, and SK Hynix has succeeded in developing 238-layer NAND, but mass production will start next year.

NAND is a key component of long-term data storage devices such as SSDs and USBs, enhancing performance through a 3D stacking process that layers semiconductors. The photo shows a 3D NAND image presented by Micron. / Photo by Micron website capture

NAND is a representative memory semiconductor along with DRAM. Although both are devices for storing data, DRAM has faster processing speeds but relatively smaller capacity and loses all stored data when the computer is powered off. In contrast, NAND is slower than DRAM but offers larger storage capacity at once and does not lose data when powered off. Due to these differences, DRAM is used for temporarily storing PC tasks, while NAND is used as a component in permanent data storage devices such as solid-state drives (SSD) and USB devices.

The performance of NAND depends on the 'number of layers,' which indicates how high the semiconductor is stacked. This is because storage capacity can be increased by stacking semiconductors densely in a vertical direction. Companies developing NAND engage in fierce 'layer count competition' every year to mass-produce NAND with more layers than their competitors.

Samsung, Hynix, Micron... The Three-Way 'Layer Count Competition' in NAND

The stacking process to increase NAND performance by stacking layers was first developed by Samsung in 2013. At that time, NAND development focused not on the number of layers but on finer processes to pack as many storage cells as possible within a single semiconductor. However, this approach faced limitations due to interference phenomena occurring between cells placed too close to each other. Samsung broke through this barrier by introducing the world's first 24-layer NAND, significantly improving performance.

Memory Semiconductor Manufacturers' NAND Flash Unit Competition

After Samsung's 24-layer NAND, memory semiconductor companies rushed into the stacking process. In June 2019, SK Hynix declared mass production of 128-layer NAND, becoming the first in the industry to surpass 100 layers, and in the following year, 2020, Micron succeeded in the first mass production of 176-layer NAND.

In fact, until recently, competitors had been ahead of Samsung in the stacking competition. In July, Micron announced the successful mass production of 232-layer NAND, breaking the industry's '200-layer' barrier for the first time. Not to be outdone, Hynix announced the successful development of 238-layer NAND at the 'Flash Memory Summit' held in Santa Clara, California, one month later. However, actual mass production will begin next year. Meanwhile, Samsung also officially joined the 200-layer competition by mass-producing its highest-layer product, the 236-layer NAND, by the second half of this year.

Meanwhile, Samsung has reigned as the king of the NAND industry for nearly 20 years since 2002. According to market research firm Omdia, Samsung's NAND market share in the second quarter of this year was 33.3%, ranking first in the industry. It was followed by Hynix (20.4%), Japan's Kioxia (16.0%), and U.S. companies Western Digital and Micron (each 13.0%).