Skip to comments.Toshiba officially introduces 19nm NAND flash ( 3-bits-per-cell (TLC), world's densest)
Posted on 02/24/2012 8:24:58 AM PST by Ernest_at_the_Beach
Back in April 2011, Toshiba and SanDisk jointly announced that they were the first to achieve a silicon fabrication breakthrough on the 19nm process node. The good news was that smaller, cheaper and higher capacity NAND flash could be stored in 2-bit-per-cell (MLC) transistors when 16 die are stacked into a single-chip package.
Rewind further back to 2008, and many analysts remember that SanDisk's former Chairman, Founder and CEO Eli Harari had questioned the industry's ability to scale below the 20nm process node. The company cited "uncertainties with Extreme Ultraviolet (EUV) lithography at such small scales, a process that had been hit with delays, lack of power sources and cost issues at the time.
Toshiba had started sampling its 19nm NAND flash shipments in April 2011 and hit volume production between July and September 2011. At the time, however, it was only sampling 2-bit-per-cell (MLC) products and had only intended to commercialize 3-bit-per-cell (TLC) later on.
In January 2012, Toshiba finally began manufacturing 19nm NAND flash on 3-bit-per-cell (TLC) 128Gb chips with the world's smallest die size at just 170mm2. The company has also been able to achieve the world's fastest write speeds on any 3-bit-per-cell (TLC) device at 18MB/s.
AnandTech recently published a comprehensive and informative overview of Triple-Layer Cell (TLC) NAND flash and its place in the consumer electronics industry which can be found here. Of course, the new TLC die shrink technology introduces a myriad of problems for voltage regulation, write amplification and ECC that all must be taken into consideration when manufacturing NAND flash at this small of a scale. Nevertheless, Toshiba claims it has optimized the peripheral circuit structure of the chips and uses air-gap technology for transistors, effectively reducing coupling between memory cells down to 5-percent.
We look forward to the first products from partnering vendors and expect them to be announced soon.
***********************************EXCERPT****************************************A Brief Introduction to SSDs and Flash Memory
In almost every SSD review we have published, Anand has mentioned how an SSD is the biggest performance upgrade you can make today. Why would anyone use regular hard drives then? There is one big reason: price. SSD prices are still up in the clouds when compared to hard drive prices (especially before the Thailand floods) so for many, SSDs have not been a realistic option.
Forking over $700 for a 512GB SSD sounds crazy because a 500GB hard drive can be had for less than $50. Smaller capacities like 64GB and 128GB can already be bought for around $100 and $200 respectively, but unless you have the ability to have an SSD plus hard drive combo, such a small SSD doesn't usually cut it. If you have a desktop, the SSD + HDD combo should not be a problem but many laptops only have space for one 2.5" drive (unless you are willing to mod it afterwards by replacing the optical drive). SSD prices have been dropping for years now, but if the current rate continues it will take years before a $399 Walmart PC includes a reasonable size SSD. So what can be done?
Most of the time, SSD production costs are cut by shrinking the NAND die. Shrinking the die is the same as with CPUs: you move to a smaller manufacturing process, e.g. from 34nm to 25nm. In flash memory, this means you can increase the density per die and usually the physical die size is also smaller, meaning more dies from a single wafer. A die shrink is an effective way to lower costs but moving from one process to another takes time and the initial ramp of the new flash isn't necessarily cheaper. Once the new process has matured and supply has met demand, prices start to fall.
Cheaper initially but less endurance...read the Anandtech article to understand.....