Micron starts mass production of 232 layer NAND. NAND flash memory is the most advanced and detailed of its kind. It’s used in products such as smartphones and SSDs. Micron’s 3D NAND was first introduced in May with more than 200 layers. The competition produces only 176 layers per series.
Micron has a distinct advantage over other layers, although the number of levels doesn’t tell much about performance or cost. Micron now has more details to support this claim, as they begin mass production of the 232 layer NAND (also known as B58R).
TLC NAND has the highest area density
Micron leads the pack in areal density (bits/area), which is one of the most critical parameters. TLC-NAND (3 bits/cell) is mass-produced for the first time. This storage capacity of 1 Tbit per dene was previously available only in QLC chips that had 4 bits per cells. Micron has also pledged to achieve the highest possible areal density of 14.6 Gbit/mm2.
This is 35 percent more than the previous leader, SK Hynix, 512Gb, 176 layer, 10.8Gbps, TLC NAND. As shown in the diagram below, microns are close to QLC-NAND’s highest level of density. Storage Density for 3D NAND (Green, TLC, Orange, QLC, Blue, SLC).
Kioxia/WD BiCS6 162L (QLC, 1Tb)
SK Hynix V7 176L (1Tb, QLC)
Micron 232L (TLC, 1TB)
Intel 144L (QLC 1TB)
SK Hynix V7 176L TLC, 512Gb
Kioxia/WD BiCS6 162L (TLC, 1Tb)
Intel/Micron 96L (QLC, 1TB)
Kioxia/WD BiCS4 96L (QLC, 1.33Tb)
Samsung V7 176L (TLC, 512GB)
YMTC 128L, TLC, 512Gb
SK Hynix V5 96L QLC, 1Tb
Kioxia/WD BiCS5 128L (TLC, 512Gb)
SK Hynix V6 128L TLC, 512Gb
Samsung V5 92L (QLC, 1TB)
Intel/Micron 96L (TLC, 512Gb)
Kioxia/WD BiCS4 96L (TLC, 512Gb)
Samsung V6 128L (TLC, 512GB)
Samsung Z-NAND 48L (SLC, 64Gb)
Intel/Micron 3D XPoint (SLC, 128Gb)
Unit: Gigabits per mm2. Although the areal density of Micron’s expected QLC variant is not known yet, it should be a record. Micron explains that the package that houses 3D NAND chips measures just 11.5×13.5mm. This is 28 percent smaller than Micron’s 176-layer package. (B47R). This NAND is the smallest available. This allows for more uses and reduces the “board space”.
The new architecture
Micron uses again two stacked layer towers, either string or array stacking. One of these towers has 116 layers. Two towers of 88-layer NAND are used in conjunction with the 176-layer NAND. Micron may have been able to reduce the thickness of these layers once again. To save space, it has been a tradition for logic circuits to be placed at their own level beneath the memory layers (CMOS Under Array, CuA).
It is well-known that the NAND matrix can be divided into various regions. These are called planes. Parallel access to multiple planes increases throughput. Micron has increased the number of patches for TLC-NAND to 6, from 4 previously. The NAND flash’s performance has been significantly improved.
ONFI 5.0 at 2,400 Mt/s
The latest Open NAND Flash Interface version (ONFI 5.0) increases the I/O throughput from the 1,600 MT/s of the 176L generation starting Micron to 2,400. This is an increase of at least 50%. This is a feat that no competitor’s 3D NAND has achieved. Kioxia intends to reduce the BiCS6-NAND of Samsung to 2,400 MT/s by the end the year. TLC 3D NAND is a comparison.
Micron’s 3D-NAND chip will allow for data to be read and written up to 75 percent faster than before. Micron doesn’t specify specific values. Other people have disclosed these details at the annual ISSCC where Micron is long gone.
Micron’s 176 layer NAND is the best choice for high-end SSDs. SSDs such as the Corsair MP600 Pro (test), which was equipped with a Phison E18 controller, were already extremely fast. However, Micron’s fast 176 layer NAND aka the B47R gave even greater performance, as SSDs such the Seagate FireCuda 530, (test), show. The SSDs that come with the similarly fast Innogrit IG5236 controller can also be used with Micron NAND. High expectations are placed on the successor.
ONFI 5.0 is more than just faster
The ONFI 5.0 standard at 2,400 MT/s includes the NV–LPDDR4 interface. This interface reportedly saves around 30% energy and transmits less data per bit. The new Micron-NAND, with its high areal density (and small space requirements), is also suitable for mobile applications and deployments in data centers and at the intelligent edge. There is however backward compatibility that can be used to support older controllers.
First finished product and availability
Micron claims that the 232-layer NAND is already in stock and has been shipped to customers. It is also available in products manufactured by the subsidiary company Crucial. However, it is not clear what those are. ComputerBase was provided with information by Micron under NDA. Only one requirement was that the article be published as soon as possible.