Gate-all-around transistor

A transistor design in which the controlling gate wraps completely around stacked, ultra-thin silicon channels.

• A transistor is a switch: the gate's electric field turns current in the channel on and off. A modern chip holds tens of billions.
• As channels shrink, the gate loses grip and current leaks when 'off'; the earlier FinFET wrapped the gate on three sides, this closes the fourth.
• Channels are stacked 'nanosheets' a few nanometres thick, and varying their width lets designers trade speed against power.
• Samsung shipped it first in 2022; TSMC's N2 and Intel's 18A adopt it from 2025, and it demands near-atomic control of layer thickness.