A physics-down bottleneck under the memory supercycle: layer-stacking is the only scaling axis left for 3D NAND, and past roughly 300 layers the tungsten wiring itself becomes the limit on resistance and fluorine chemistry. A materials switch at that layer of the stack is a deposition-equipment and precursor story before it is a NAND-maker story, and it puts a physical ceiling under 'just add layers' capacity assumptions.
NAND Manufacturing is moving from Tungsten to Molybdenum (Mo): 3D NAND stopped shrinking sideways a decade ago, it scales by stacking layers. But above ~300 layers, the tungsten word lines wiring every memory cell hit a wall: resistance is too high, fluorine-based chemistry
A physics-down bottleneck under the memory supercycle: layer-stacking is the only scaling axis left for 3D NAND, and past roughly 300 layers the tungsten wiring itself becomes the limit on resistance and fluorine chemistry. A materials switch at that layer of the stack is a deposition-equipment and precursor story before it is a NAND-maker story, and it puts a physical ceiling under 'just add layers' capacity assumptions.
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