# Floating Gate
**Entity class:** Semiconductor device structure
**Domain:** Semiconductor memory / neural hardware
**Doc Type:** Developed Technology Node
**Maturity:** Developed
## Definition
A **floating gate** is an electrically isolated conductor in a transistor that stores charge and thereby changes the device's behavior. Dawon Kahng and Simon Sze demonstrated the floating-gate MOS device at [[wiki/Bell Labs|Bell Labs]] in 1967.
## Machine-Intelligence Context
The floating gate became the physical storage principle behind EPROM, EEPROM, and flash memory. Neural-hardware designers also used it as a persistent, adjustable synaptic weight. Intel's [[wiki/Intel 80170NX ETANN|80170NX ETANN]] and the 1996 single-transistor synapse developed by Carver Mead's Caltech group show the same device class serving memory, adaptation, and computation.
## Evidence Ledger
- **Established:** Kahng and Sze demonstrated the floating-gate device in 1967.
- **Established:** Floating gates became foundational to nonvolatile memory and adaptive neural circuits.
- **Strongly indicated:** The device is a durable physical junction between memory and learning hardware.
- **Unresolved:** The degree of direct knowledge transfer among the Bell Labs memory lineage, Intel ETANN, and Caltech synapse work; patent citations, personnel records, and laboratory notebooks would settle it.
## Sources / Provenance
- [Computer History Museum, “Neural Network Chip Joins the Collection”](https://computerhistory.org/blog/neural-network-chip-joins-the-collection/).
- [[articles/A History of Machine Intelligence|A History of Machine Intelligence]].
## Relationships
- **Originated at:** [[wiki/Bell Labs|Bell Labs]].
- **Enables:** [[wiki/NAND Flash|NAND Flash]], [[wiki/Intel 80170NX ETANN|Intel 80170NX ETANN]], and the single-transistor silicon synapse.
- **Central to:** [[wiki/Substrate Intentionality|Substrate Intentionality]].