NAND Flash Memory Cell
Gate: 0V
Control Gate (0V)
Control Gate
Oxide
Floating Gate
Tunnel Oxide (≈8nm, planar; 3D NAND uses charge-trap layer)
Source
Drain
N+ Source
N+ Drain
P-Type Substrate
Erased
1
No electrons
Programmed
0
Electrons trapped
11
~0 e⁻
10
~5K e⁻
01
~10K e⁻
00
~15K e⁻
🔴 HDD (Hard Disk Drive)
Random Read
0.5-2 MB/s
Latency
5-15 ms
Technology
Magnetic
🟠 SSD (Solid State Drive)
Random Read
50-500 MB/s
Latency
0.02-0.1 ms
Technology
Quantum Tunneling
Cell Operations
How It Works
Quantum Tunneling Magic: When high voltage is applied to the control gate, electrons quantum tunnel through the thin oxide barrier into the floating gate (or charge-trap layer in modern 3D NAND), where they become trapped for years—even without power!
Cell Types
SLC
1 bit
100K writes
MLC
2 bits
10K writes
TLC
3 bits
3K writes
QLC
4 bits
1K writes
Cell Wear
0%
Operation Log
Ready
Cell initialized
💥 HOLY SHIT MOMENT
"Your SSD traps electrons in quantum prisons to remember data."