finfET

FinFET, short for fin field-effect transistor, is a type of non-planar transistor used in modern integrated circuits. In a FinFET, the conducting channel is a thin silicon fin that protrudes from the substrate. The gate wraps around the fin on at least two sides and, in typical designs, around three sides, providing enhanced electrostatic control over the channel compared with conventional planar MOSFETs.

This three-dimensional gate structure reduces short-channel effects, improves the subthreshold slope, and allows higher drive currents at small geometries, enabling continued scaling to smaller sizes. FinFETs are commonly built with high-k dielectric and metal gates and have become the standard CMOS building block at nodes around or below 20–22 nanometers. The technology offers better leakage performance and drive strength for dense, power-efficient integrated circuits.

Historically, the FinFET concept and its tri-gate architectures emerged in the late 1990s and 2000s, with commercial adoption beginning in the early 2010s. Intel introduced commercial FinFETs at the 22 nm node (often described as Tri-Gate) around 2011–2012, followed by other leading manufacturers such as TSMC and Samsung for 20 nm and smaller nodes. Today, FinFETs remain central to high-performance processors and system-on-chip devices.

Fabrication involves patterning narrow silicon fins, isolating channels, and forming a gate dielectric and metal gate that wrap around the fin. Variability in fin dimensions and the added manufacturing complexity present challenges. As research progresses, gate-all-around transistors are being explored as successors, but FinFETs continue to underpin most contemporary mainstream CMOS processes.