GateAllAround

Gate-all-around (GAA) transistors are a class of metal-oxide-semiconductor field-effect transistors in which the gate material surrounds the channel on all sides. This arrangement provides superior electrostatic control of the channel compared with traditional planar or FinFET designs, helping to suppress short-channel effects as devices are scaled down.

GAA devices are typically realized with nanosheet or nanowire channel structures. In nanosheet (NS) implementations, several ultra-thin oxide- and silicon-based sheets are stacked or arranged so the gate wraps around each sheet. In nanowire (NW) variants, the channel consists of a cylindrical or rectangular wire surrounded by the gate. Both configurations aim to maximize gate control while maintaining acceptable drive current and density.

The primary advantages of gate-all-around transistors include a steeper subthreshold slope, reduced leakage in the off state, and higher drive strength for a given footprint. These benefits enable continued scaling to smaller nodes (such as 3 nm and beyond) without sacrificing performance or energy efficiency. GAA structures also offer flexibility in design, allowing adjustments to the channel geometry to optimize power and speed for different applications.

Industry adoption has been advancing, with leading semiconductor companies publicly developing and prototyping GAA devices. Demonstrations have shown nanosheet-based GAA transistors as part of next-generation process technologies, and several vendors reference GAA as the path beyond FinFET for future nodes. Challenges remain, including manufacturing complexity, uniform deposition on three-dimensional structures, and yield considerations. Nevertheless, GAA is widely regarded as the key enabling architecture for continued transistor scaling in advanced logic circuits.