Samsung Electronics has begun the volume production of 64-layer, 256Gb V-NAND flash memory, expanding its line-up of storage solutions for server, PC and mobile applications.

The company began supplying SSDs based on 64-layer 256Gb V-NAND chips to enterprise clients in January. Now, Samsung will supply the SSDs for consumers, and memory card and embedded Universal Flash Storage for mobile.

Samsung intends for its volume production of the 64-layer V-NAND chip, which is widely referred to as fourth generation V-NAND, to cover more than 50% of its monthly NAND flash production by year end.

The 64-layer 3-bit 256Gb V-NAND features a data transfer speed of 1Gbps, which is the fastest among currently available NAND flash memory. The V-NAND also offers a short page programme time (tPROG) of 500㎲ among NAND flash memory, which is about four times faster than that of a typical 10nm class, planar NAND flash memory and approximately 1.5 times faster than that of Samsung’s fastest 48-layer 3-bit 256Gb V-NAND flash.

The new 64-layer 256Gb V-NAND provides more than a 30% productivity gain, compared to the 48-layer 256Gb V-NAND that preceded it, according to Samsung. In addition, the 64-layer V-NAND has a 2.5V input voltage for its circuits, which leads to approximately 30% greater energy efficiency than the 3.3V that 48-layer V-NAND used. The reliability of the new V-NAND cell increased by about 20% compared to its predecessor.

As the layers of cell arrays increase, the level of technological difficulty also increases, especially in making the channel holes homogeneous in their shape from the top to the bottom layer, and in properly dispersing the weight of all the layers to improve the stability of the channel holes.

Samsung said it was able to realise 64 layers of cell arrays based on 3D CTF (charge trap flash) structure and uniformly cover the inner side of each channel hole with an atomically thin, non-conductive substance, which led to the creation of smaller cells with improved performance and reliability.