Back in November, Intel and Micron revealed the first details on their joint effort to produce 3D flash memory. We learned that the initial offering will have 32 layers and hold 32GB (256Gb) in a two-bit MLC configuration. Today, the firms shed some additional light on the underlying technology and their production plans.
Like typical planar NAND, this new breed of 3D flash is build on floating-gate tech. That's a stark contrast to the approach taken by Samsung and Toshiba, whose stacked implementations employ a charge-trap structure. According to Intel VP of non-volatile memory technology development Giri Giridhar, the decision to stick with floating gates was made years ago. Floating gates are a known quantity, he said, and the physics is well understood. There's also lots of existing infrastructure built around floating-gate tech.
Although Intel and Micron declined to provide specifics on the lithography used to create their 3D NAND, Giridhar mentioned an "innovative process architecture." He also noted that the 3D cells are "electrically equivalent" to planar ones built on a 50-nm process. Samsung's 3D V-NAND has 40-nm planar geometry, and it seems Intel and Micron may be in a similar ballpark.
Giridhar claimed that electrical equivalence with 50-nm planar cells enables higher performance and endurance than contemporary 2D NAND, which is built on much finer fabrication nodes that are more sensitive to interference and physical wear. Future generations are projected to maintain that equivalence, allowing Intel and Micron to add layers—and capacity—without sacrificing speed or durability. The two firms aren't ready to release performance and endurance specifications for their first 3D product, though.
The first generation will come in not only a 32GB MLC config, but also a three-bit TLC flavor with 48GB (384Gb) per die. That's a huge step up from the capacity of Samsung's existing TLC V-NAND, which weighs in at only 16GB (128Gb) per die.
Initial production has already begun, and chips are sampling now. Mass production is scheduled for the second half of 2015. Intel plans to release a drive based on 3D NAND in that timeframe, so we should see the tech in action before the year is out.