Name Hot Electron Injection as Eproms Write Mechanism

# Name Hot-Electron Injection as EPROM's Write Mechanism

## 3. How a Bit Gets Written, Named Without Re-Deriving the Physics

EPROM's write mechanism has a specific name worth recording precisely: hot-electron injection (also called channel hot-electron or avalanche injection, depending on the exact device generation). When a sufficiently high voltage is applied to the drain of a floating-gate transistor while its control gate is also biased high, electrons moving through the channel gain enough kinetic energy — becoming "hot" relative to the lattice — that a fraction of them are injected over the oxide barrier and onto the isolated floating gate, where they remain trapped. This is a distinct physical mechanism from the quantum-tunneling erase/program physics already covered in detail elsewhere on this site for NAND flash; hot-electron injection is named here only as the mechanism this series' subject devices use to write a bit, not re-derived at the band-diagram or field-equation level. For this series' purposes, the operationally important fact is simpler: writing an EPROM or early EEPROM cell required a deliberately elevated programming voltage, applied one byte or word at a time through the device's own address and data pins.