Kioxia wins lifetime achievement for 3D NAND amid IPO plans
The flash storage industry wouldn't be where it is today without 3D NAND. To celebrate its invention, Kioxia is receiving a Future of Memory and Storage Lifetime Achievement Award.
NAND inventor and SSD maker Kioxia received an industry award Tuesday for 3D NAND, which has led to the density and performance of flash storage used in everything from smartphones to supercomputers.
At the 2024 Future of Memory and Storage Flash Memory Summit in Santa Clara, Calif., Kioxia was presented with the FMS Lifetime Achievement Award for its invention of 3D NAND. The technology enables the ability to stack memory cells for better density.
The award comes as Kioxia reportedly plans to file an IPO to list shares on the Tokyo Stock Exchange later this year. It also lines up with last week's completion of a new manufacturing building in Kitakami, Japan, that will be operational at the end of 2025.
The lifetime achievement award has been given out annually since 2011 and highlights advancements in memory or storage technology, business, academic and application advancements. The five key members of the then-Toshiba, now Kioxia, engineering team who received the achievement award include Hideaki Aochi, Ryota Katsumata, Masaru Kito, Masaru Kido and Hiroyasu Tanaka.
Kioxia is a real powerhouse for inventing strikingly new technologies.
Jim HandyGeneral director and semiconductor analyst, Objective Analysis
While many lifetime achievement awards have been given out, Kioxia stands apart from the rest through a series of firsts in the storage industry, according to Jim Handy, general director and semiconductor analyst at Objective Analysis. Kioxia, when it was still part of Toshiba, invented NOR flash, NAND flash and then 3D NAND.
"Kioxia is a real powerhouse for inventing strikingly new technologies," Handy said.
3D NAND
While flash storage dates back to 1959, with metal–oxide semiconductor field-effect transistors (MOSFET) invented by Bell Labs, the initial flash was slow and difficult to use. Kioxia, then still Toshiba, invented NOR flash in 1984, followed by NAND flash in 1987.
NOR and NAND were better than MOSFET, but there were still limitations. NOR had faster read speeds than NAND but was more expensive to manufacture and had slow erase times. NAND had slower random performance and lower endurance than NOR, however it was denser. Neither could cost-effectively scale in the early days.
In 2007, Kioxia introduced 3D NAND, named Bit Cost Scalable Flash or BiCS, that stacked the NAND chips on top of each other to allow for more density in the same footprint, faster performance and longer endurance. BiCS is in its eighth generation, with 218 layers.
"Kioxia invented the whole idea of stacking, then just everybody else kind of gussied it up a little bit," Handy said, referring to different stacking methods including those created by Samsung the following year.
Important first step
Handy notes that while Kioxia was the first, 3D NAND now accounts for nearly all NAND produced today. Samsung was the first vendor to ship substantial volumes of 3D NAND, which it calls vertical NAND or V-NAND.
"Samsung said, 'We're going to not use the same materials in the stack that Kioxia uses. We're going through a slightly different process,'" Handy said. "They did, and it ended up working better."
While Kioxia deserves the credit for inventing the 3D NAND technology, it is the entire industry that ran with the idea to get flash storage where it is today, according to Joseph Unsworth, an analyst at Gartner.
Stacking NAND chips is important for density, but so is placing multiple bits per cell pioneered by SanDisk (now Western Digital) that brought the industry to triple-level cell and quad-level cell storage. The SSD controller vendors also deserve credit for realizing and working around inherent issues in flash technology.
Flash vendors are working on lowering costs and delivering high-performance flash storage for high-end applications.
"This is a testament, not only to Kioxia, but the entire industry that has embraced flash's evolution," Unsworth said.
Adam Armstrong is a TechTarget Editorial news writer covering file and block storage hardware and private clouds. He previously worked at StorageReview.
