The second paragraph: > Those additional layers will add new reliability issues a number of incremental reliability challenges, but the NAND flash industry has

The second paragraph: > Those additional layers will add new reliability issues a number of incremental reliability challenges, but the NAND flash industry has been steadily increasing the stack height for nearly a decade. In 2015, Toshiba announced the first 16-die stack using through-silicon vias. That enabled higher bandwidth, reduced latency, and faster I/O, while also helping to pave the way for stacking of other types of memory and logic chips. Stacking multiple dies (with or without TSVs) is an entirely different kind of stacking from building multiple layers of memory cells on a single die, which is what 3D NAND is all about. Samsung was the first to deliver 3D NAND, and IIRC Toshiba was tied for fourth to reach that milestone.