August 6th, 2019 by Lyle Smith
Samsung Begins Mass Producing 250GB SATA SSDs with 6th-gen 256Gb 3bit V-NAND
Samsung has started the mass production of 250GB SATA SSDs that integrate the company’s 6th-gen (1xx-layer) 256Gb 3bit V-NAND for global PC OEMs. With its ‘channel hole etching’ technology, Samsung indicates that the new V-NAND adds approximately 40% more cells to the previous 9x-layer single-stack structure. This is done by building an electrically conductive mold stack with 136 layers, then vertically piercing cylindrical holes from top to bottom, which creates a uniform 3D charge trap flash (CTF) cells.
When the mold stack’s height increases in each cell area, errors and read latency vulnerabilities can occur. To address this, Samsung has integrated a speed-optimized circuit design that allows it to achieve the fastest data transfer speed: under 450μs in writes and 45μs in reads. Samsung indicates a 10%+ gain in performance over the previous generation, with a reduction of more than 15% in power consumption. As a result, by just mounting three of the current stacks, the company claims they will be to offer next-generation V-NAND solutions with over 300 layers without compromising chip performance or reliability.
Samsung has also decreased the number of channel holes required to create a 256Gb chip density to 670 million holes from (compared to more than 930 million with the previous generation). This will allow for reduced chip sizes, fewer process steps, and over a 20-percent improvement in manufacturing productivity.
Samsung is expected to offer 512Gb 3bit V-NAND SSD and eUFS during the second half of 2019. In addition, they will expand production of higher-speed and greater-capacity 6th gen V-NAND solutions at its Pyeongtaek (Korea) campus beginning next year.