SK Hynix announced this week that it has started mass production of 238-layer TLC NAND memory. The new device promises higher bit densities and lower costs for his NAND bits for the manufacturer, and features a very high interface speed of 2400 MT/s, allowing for ultra-high performance SSDs.
SK Hynix’s first 238-layer 3D TLC NAND device features a capacity of 512 Gb (64 GB). Compared to its 176-layer predecessor, it offers 34% more manufacturing efficiency (smaller die size, less material usage, fewer expensive process steps, etc.) and 21% lower power consumption during manufacturing. has the advantage of ONFI 5.0 interface with NV-LPDDR4 signaling and interface transfer rate of 2400 MT/s, which is 50% higher, enables read operations.
The latter is perhaps the most important advantage of the new memory chips for PC enthusiasts. This is because modern and upcoming client SSDs with PCIe 5.0 x4 interfaces require fast memory devices to saturate. Currently available 3D NAND with a 1600 MT/s interface only enables drives with sequential read/write speeds of around 10 GB/s, but going above 12.5 GB/s requires faster memory. must be used. Alternatively, use more memory devices and a suitable controller.
SK Hynix’s 238-layer 3D TLC NAND not only uses string stacking to combine pairs of 119-layer decks, but also uses charge trapping, CMOS under-array (CuA) architecture, which turns NAND logic into 3D NAND memory. Place it below the cell array to reduce die size. And it costs. This is why SK Hynix calls this architecture 4D NAND.
| SK Hynix 3D TLC NAND Flash Memory | ||
| 238L | 176L | |
| layer | 238 | 176 |
| deck | 2 (x119) | 2 (x88) |
| die capacity | 512GB | 512GB |
| Die size (mm2) | 35.58mm2 | ～47.4mm2 |
| Density (Gbit/mm2) | ～14.39 | 10.8 |
| I/O speed | 2.4MT/s (ONFi5.0) |
1.6 MT/s (INF4.2) |
| CuA/PuC | yes | yes |
SK Hynix is the third major NAND flash memory maker to start producing 3D NAND with over 200 layers. SK Hynix said one of the major smartphone makers is about to complete compatibility tests with its 238-layer 3D NAND devices. Once that is done, SK Hynix will start shipping these memory chips to mobile phone makers. Ultimately, these devices will be used for PCIe 5.0 SSDs and high-capacity server drives, the company said.
In a statement, SK hynix said, “SK hynix has developed a solution product for client SSDs used as storage devices for smartphones and PCs using 238-layer NAND technology, and started mass production in May.” and “Since we have secured world-class competitiveness in terms of price, performance, and quality for both 238-layer NAND and the previous generation 176-layer NAND, we expect these products to drive earnings improvement in the second half. I have.”
Source: SK Hynix
