Samsung Electronics Co. has begun mass producing its three-dimensional (3D) Vertical NAND (V-NAND) flash memory. Claimed as an industry first, the company advises this is a breakthrough in the current scaling limit for existing NAND flash technology. The new 3D V-is ideal for a wide range of consumer electronics and enterprise applications, including embedded NAND storage and solid state drives (SSDs).
This solution offers a 128Gb density in a single chip, integrating the company’s vertical cell structure based on 3D Charge Trap Flash (CTF) technology and vertical interconnect process technology to link the 3D cell array. By applying both of these technologies, the company claims to be able to provide over twice the scaling of 20nm-class planar NAND flash.
“The new 3D V-NAND flash technology is the result of years of efforts to push beyond conventional ways of thinking and pursue much more innovative approaches in overcoming limitations in the design of memory semiconductor technology,” said Jeong-Hyuk Choi, Senior Vice President, flash product & technology, Samsung Electronics.
“Following the world’s first mass production of 3D Vertical NAND, we will continue to introduce 3D V-NAND products with improved performance and higher density, which will contribute to further growth of the global memory industry.”
For the past 40 years, conventional flash memory has been based on planar structures that make use of floating gates. As manufacturing process technology has proceeded to the 10nm-class and beyond, concern for a scaling limit arose, due to the cell-to-cell interference that causes a trade-off in the reliability of NAND flash products. This also led to added development time and costs.
Samsung’s new V-NAND responds to these challenges by achieving vertical stacking of planar cell layers for a new 3D structure. To achieve this, the company revamped its CTF architecture, which was first developed in 2006. In the company’s CTF-based NAND flash architecture, an electric charge is temporarily placed in a holding chamber of the non-conductive layer of flash that is composed of silicon nitride (SiN), instead of using a floating gate to prevent interference between neighbouring cells.
By making this CTF layer three-dimensional, the reliability and speed of the NAND memory have improved sharply. The new 3D V-NAND shows not only an increase of a minimum of two times to a maximum ten times higher reliability, but also twice the write performance over conventional 10nm-class floating gate NAND flash memory.
Also, one of the most important technological achievements of the new NAND is that the company’s vertical interconnect process technology can stack as many as 24 cell layers vertically, using special etching technology that connects the layers electronically by punching holes from the highest layer to the bottom. With the new vertical structure, Samsung can enable higher density NAND flash memory products by increasing the 3D cell layers without having to continue planar scaling, which has become incredibly difficult to achieve.
According to IHS iSuppli, the global NAND flash memory market is expected to reach approximately US $30.8 billion in revenues by the end of 2016, from approximately US $23.6 billion in 2013 with a CAGR of 11 percent, in leading growth of the entire memory industry.
Samsung Electronics Co., Ltd.