FinFET

Overview

A FinFET (Fin Field-Effect Transistor) is a type of non-planar, 3D transistor that is a major advancement from the traditional planar MOSFET (Metal-Oxide-Semiconductor Field-Effect Transistor).

The key difference lies in its structure:

3D Channel (The Fin): Unlike a planar MOSFET, where the gate controls the current flow through a flat, two-dimensional channel, the FinFET's channel is a thin, raised structure (like a fin) on the silicon substrate.

Gate Wrapping: The gate electrode wraps around three sides of this fin (top and both sides), giving it far greater control over the channel.

Key Advantage of FinFETs

FinFETs were introduced to solve the major scaling and leakage problems encountered as traditional MOSFETs got smaller. Their 3D structure provides two primary benefits:

Reduced Leakage Current: The gate's control over the channel from three sides dramatically reduces the amount of current that leaks through the channel when the transistor is supposed to be OFF. This makes the chip more power-efficient.

Improved Performance/Speed: The superior gate control allows the transistor to switch between its ON and OFF states much faster and more cleanly, leading to higher performance and speed for microprocessors and other integrated circuits.

Industry Context

FinFET technology is fundamental to modern processor manufacturing and is used for chip fabrication at technology nodes of 22 nm and smaller (e.g., 14 nm, 10 nm, 7 nm). successors include GAA (Gate-All-Around) and MBCFET (Multi-Bridge Channel FET), which represent the next generation of non-planar transistors being developed for nodes smaller than 5 nm.