Zvi Or-Bach, President & CEO of MonolithIC 3D Inc. blogs about Samsung’s recent announcement on 3D vertical NAND.
Samsung announced today (Aug. 6, 2013) the mass production of the industry’s first three-dimensional (3D) Vertical NAND (V-NAND) flash memory, which breaks through the current scaling limit for existing NAND flash technology. Achieving gains in performance and area ratio, the new 3D V-NAND will be used for a wide range of consumer electronics and enterprise applications, including embedded NAND storage and solid state drives (SSDs).
According to Samsung, the new V-NAND offers a 128 gigabit (Gb) density in a single chip, utilizing the company’s proprietary 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, Samsung’s 3D V-NAND is able to provide over twice the scaling of 20nm-class planar NAND flash.
It’s worth mentioning to the point that while the volume production of TSV based 3D IC is keep being pushed out as discussed in a recent blog: EUV vs TSV: Which one will become production ready first?, this announcement indicates that monolithic 3D NAND is beating the forecast by a few years as illustrated by the following 2012 ITRS chart:
Clearly monolithic 3D is a promising alternative to dimension scaling, as one can read in the Samsung announcement. It also adheres very well to the low cost objective for mass production products.
Monolithic 3D technology provides multiple unique and powerful advantages as we present on our site under the tab: 3D-IC Edge. Under item 5 we present the unique advantage that was first introduced in 2007, when Toshiba unveiled its Bit Cost Scalable (BiCS) technology. The unique advantage of 3D NAND is the ability to pattern and process multiple layers simultaneously.
This advantage comes very naturally for regular layout fabrics such as memory, but it is also available for logic circuits. The driver for this advantage is the escalating costs of lithography in state of the art IC. The following charts illustrate the impact of dimensional scaling on lithography costs.
Currently critical lithography steps dominate the end device production costs as illustrated in the following chart:
Accordingly, if the critical lithography step could be used once for multiple layers rather than multiple times for each single layer, then the end device cost would roughly be reduced in proportion to the number of layers processed simultaneously. Multiple memory architectures that support such drastic cost reduction has been presented in various conferences and other forums. Few of those had been presented in our blog: The Flash Industry’s Direction, and MonolithIC 3D Inc.’s Solution…