finFETs

FinFET stands for fin field-effect transistor. It is a non-planar, three-dimensional transistor in which the conducting channel is formed by a thin silicon fin raised above the substrate. The gate wraps around the fin on at least two sides, typically three (the sidewalls and the top), providing stronger electrostatic control over the channel than a traditional flat transistor. Source and drain regions are formed at the ends of the fin. Modern FinFETs often use a high-k dielectric and metal gate materials to improve performance.

Benefits and operation. The 3D gate geometry reduces short-channel effects and allows steeper switching, higher drive current, and lower leakage for a given footprint. This improved electrostatics enables continued device scaling to smaller nodes and the ability to operate at lower supply voltages. FinFETs can offer higher on-state current density and better saturation behavior compared with planar transistors, contributing to higher performance in integrated circuits.

History and adoption. The FinFET concept emerged in the 1990s through work by researchers at universities and industry labs, with practical devices demonstrated in the early 2000s. Intel introduced commercial FinFETs in its 22-nanometer process around 2012, and other major foundries such as Samsung and TSMC followed with FinFET-based nodes. As process outlets advanced, FinFETs became the dominant transistor technology for most high-performance and mobile applications.

Fabrication and evolution. FinFET fabrication involves forming narrow silicon fins, isolating them, and surrounding the fins with a gate material. Advances include the use of high-k metal gate stacks and replacement gate schemes. In later generations, manufacturers have explored gate-all-around approaches and nanosheet architectures that extend the same 3D gate control principles to other channel geometries.