Hardcore Explainer: Why 3D NAND Deep Silicon Etching is Like Digging a 100m Deep Well

zephyr_z9 · x · 2026-08-07

A blogger used vivid, hardcore language to explain the manufacturing difficulty of 3D NAND flash (like Kioxia's XL SLC), contrasting it with traditional 2D planar flash (like Winbond's 46nm floating gate SLC).

The author points out that building 3D NAND requires drilling extremely narrow holes through a very deep stack of materials. The aspect ratio is akin to digging a 1-meter wide hole 100 meters straight down, repeated billions of times, with every single hole needing to be perfectly vertical. Afterwards, the inside of each hole must be coated with films a few atoms thick before dissolving out alternating layers. This extreme engineering challenge is the core barrier in high-end memory chip manufacturing.

Original post →

More from Infra

Infra channel →