SK hynix Announces 238 Layer NAND

As the 2022 Flash Memory Summit continues, SK hynix is ​​the latest vendor to unveil its next-generation NAND flash memory at the show. The company’s upcoming 238-layer TLC NAND, which promises increased density/capacity and increased bandwidth, will be on display for the first time. With 238 layers, SK hynix has secured the rights to boast the highest layer count of any TLC NAND die, at least for now. However, the company’s latest NAND will appear in retail offerings as mass production won’t start until his 2023.

Following the announcement of Micron’s 232L TLC NAND last week, SK hynix is ​​bumping up the price ever so slightly on its 238-layer design. Differences in layer counts are of little importance when you’re talking about NAND dies with 200+ layers in the first place but in a very competitive flash memory industry SK hynix gives layer count bragging rights and the previous Breaking the stalemate between the two Samsung, Micron in 176L.

From a technical point of view, SK hynix’s 238L NAND further develops the basic design of the 176L NAND. So I’m looking at the string stack design again. SH hynix uses a pair of 119 layer decks from the previous generation’s 88 layers. This makes SK hynix the third flash memory vendor to master over 100-layer high building decks, enabling the production of 238L NAND designs that hold the line with two decks.

SK hynix’s NAND decks continue to be built with a charge-trapped, CMOS Under Array (CuA) architecture, which sees most of the NAND’s logic located underneath the NAND memory cells. According to the company, his early 512Gbit TLC parts have a die size of 35.58mm.²which gives a density of about 14.39 Gbit/mm.²This is a 35% increase in density over the previous generation 176L TLC NAND die of comparable capacity. Notably, this shows SK hynix trailing slightly behind Micron’s his 232L NAND, despite the total layer count advantage as Micron claims it reached his 14.6 Gbit/mm density. means to take² With a die of 1Tbit.

Speaking of 1Tbit, unlike Micron, SK hynix isn’t taking advantage of the increased density to build higher capacity dies. At least not yet. The company has announced that it will use the 238L process to manufacture his 1Tbit dies next year, but for now he retains 512Gbit, the same capacity as the previous generation. So, all other factors being equal, we wouldn’t expect a first generation drive built using 238L NAND to have a higher capacity than the current generation. But at least SK hynix’s first his 238L die is very small, but whether that translates into smaller packages remains to be seen.

In addition to increasing density, SK hynix has also improved NAND performance and power consumption. Like other NAND vendors, SK hynix is ​​using this next generation NAND to introduce his ONFi 5.0 support. ONFi 5.0 is notable for not only increasing the maximum transfer rate to 2400MT/s (50% improvement over ONFi 4.2), but also introducing a new NV-LPDDR4 signaling method. Being based on LPDDR signaling (unlike ONFi 4.x’s DDR3-derived mode), NV-LPDDR4 clearly reduces the amount of power consumed by NAND signaling. SK hynix didn’t reveal power consumption to this level of detail, but for overall power consumption, it claims a 21% reduction in energy consumed in read operations. Presumably this is in bits, so it’s offset by a 50% increase in bandwidth.

This week’s announcement comes when SK hynix starts shipping samples of its 238L NAND to customers. As previously mentioned, the company doesn’t plan to start mass production until the first half of 2023, so it will be some time before the new NAND appears in retail offerings. Starting with shipping NAND for SSDs, followed by smartphones and high-capacity server SSDs. This will be followed by the introduction of he 1T bit 238L NAND in late 2023.