After flash memory has entered the era of three-dimensional stacking, driven by major storage manufacturers, the number of stacking layers of flash memory has become higher and higher, and has now exceeded the 200-layer mark. However, the pursuit of the number of layers by major manufacturers will never stop. According to the Korean media The Elec, Samsung’s storage business executives recently stated that V-NAND can be stacked to 1,000 layers in 2030. The competition for layer stacking in the flash memory market is intensifying, and the capacity of storage products is expected to continue to increase in the future.

The battle over the number of flash memory layers is intensifying, and the sword will reach more than 1,000 layers in 2030
With the development of technologies such as AI and big data, the demand for large-capacity storage products (such as SSD) has arisen. Compared with the traditional planar structure 2D NAND Flash, 3D NAND Flash and 4D NAND Flash can provide larger storage space to meet the growing demands of the industry. Therefore, it has gradually attracted the attention of major manufacturers.

At present, 3D/4D NAND Flash has exceeded 200 layers, and the number of layers of Samsung’s 8th generation V-NAND has reached 236 layers; Micron’s 232-layer NAND Flash has been mass-produced and shipped; in March this year, Kioxia and Western Digital jointly announced the launch of 218-layer 3D NAND flash memory has begun to provide samples for some customers; SK Hynix successfully developed the world's highest 238-layer 4D NAND flash memory in August 2022. The overseas customer company of the mobile phone conducts product verification.

In the future, storage manufacturers will continue to develop NAND Flash with higher layers. Micron plans to launch 2YY, 3XX, and 4XX products with higher layers after 232 layers; Kioxia and Western Digital are also actively exploring 300 layers, 400 layers, and 500 layers. Samsung plans to launch the ninth-generation 3D NAND (expected to reach 280 layers) in 2024, the tenth-generation 3D NAND (expected to reach 430 layers) in 2025-2026, and realize 1,000-layer NAND Flash by 2030.

However, it is not easy to achieve more than 1,000 layers of NAND Flash. Samsung's storage business executives revealed that just like building a skyscraper, many stability issues such as collapse, bending, and fracture need to be considered. In addition, it is necessary to overcome connection hole processing technology, Challenges such as minimizing battery interference, shortening floor heights, and expanding storage capacity per floor.

Two expansion methods, the capacity of a single SSD can reach 1PB in the next ten years?
In the era of 2D NAND planes, manufacturers mainly rely on technology for capacity expansion. In order to increase the capacity of flash memory products, manufacturers will introduce advanced process technology, such as upgrading from 50nm process to 30nm process, which can achieve greater capacity under the same size and area.

However, no matter how advanced the process technology is, there is a limit to the storage density per unit area, and as the process improves and the storage density increases, the charge interference problem of adjacent storage cells will become more serious, which will lead to an increase in data processing error rate and problems such as reduced service life.

In order to break through these bottlenecks, flash memory is moving from flat to three-dimensional, the number of stacked layers is getting higher and higher, and the capacity and performance of flash memory chips are also continuously improved.

In addition to stacking technology, another effective way to expand capacity is to change the structure of flash memory chips. From SLC, MLC, TLC, QLC to PLC, the information that can be stored in each unit of the five types of flash memory particles is progressive, and the capacity is gradually increased. Performance, reliability, and lifespan have not been optimized accordingly, and some technical means are needed to make up for repairs.

Driven by the innovative technology of flash memory stacking and architecture, the capacity of flash memory products represented by SSD continues to increase. At present, the common capacities of consumer-grade SSDs include 256GB, 512GB, 1TB, 2TB, 4TB, etc. Enterprise-grade SSDs have larger capacities, up to 16TB, 32TB, 64TB, and even 128TB or more.

In March this year, Samsung Electronics stated that it expects the capacity of a single SSD to reach 1PB (1024TB) in the next ten years. The industry believes that the QLC/PLC flash memory architecture and 1000-layer stacking technology are expected to help SSD continue to move towards the PB-level future.