GateAllAroundStrukturen

Gate-All-Around Structures (GAA) are transistor architectures in which the gate electrode surrounds the channel on all sides, providing superior electrostatic control compared with FinFETs, which gate around three sides of a fin. In German-language sources, these are often called GateAllAroundStrukturen. The key idea is to maximize gate-channel intimacy to suppress short-channel effects and enable further scaling.

Two main implementations are nanosheet GAA and nanowire GAA. In nanosheet GAA, multiple thin silicon sheets form a vertical stack that acts as the channel; a single gate wraps around each sheet. In nanowire GAA, the channel is a nanowire and the gate surrounds it. Stacked nanosheets can increase drive current without expanding the footprint, combining high density with strong control.

Advantages of GAA include an improved subthreshold slope, reduced leakage, and better tolerance to shrinking geometries. The enhanced electrostatic control enables continued scaling to smaller nodes and the potential for lower operating voltages and higher performance, making GAA a leading candidate for future CMOS technology beyond FinFET.

Manufacturing GAA devices requires new fabrication steps, such as conformal deposition of high-k dielectrics and metal gates around nonplanar channels, precise etching to form nanosheets or nanowires, and self-aligned integration with source/drain regions. The process is more complex than FinFET fabrication, with ongoing research to optimize yield and integration.

Industry status: Gate-All-Around FETs are broadly regarded as the successor to FinFETs for advanced nodes. Demonstrations and pilot production of nanosheet/nanowire-based devices have occurred, and major semiconductor firms have announced plans to deploy GAA architectures in future process generations.