Comparative Assessment of Multigate MOSFET Structures

Multigate MOSFETs (multiple-gate field-effect transistors) have recently emerged as promising alternatives to conventional planar MOSFETs, which are increasingly constrained by scaling limitations. As device dimensions continue to shrink into the nanoscale regime, planar transistors experience several challenges such as pronounced short-channel effects (SCEs), increased leakage current, and reduced electrostatic control over the channel. Multigate transistor structures address these issues by employing multiple gate electrodes that surround the channel region, thereby improving gate control over charge carriers and enhancing overall device performance. This work presents a comparative assessment of various multigate MOSFET architectures, including double-gate (DG), FinFET, tri-gate, Pi-gate, omega-gate, and gate-all-around (GAA) structures. The structural characteristics, operating mechanisms, and performance benefits of each architecture are examined with respect to their suitability for nanoscale device applications. Compared with planar MOSFETs, multigate transistors offer improved electrostatic control, higher drive current capability, effective suppression of short-channel effects and significantly reduced leakage current. In addition, the role of substrate engineering in multigate transistor fabrication is discussed, particularly the use of silicon-on-insulator (SOI) technology, which contributes to improved device isolation and performance. Among these architectures, FinFET and GAA transistors are considered highly scalable and suitable for future technology nodes. Consequently, multigate transistor structures are expected to play a vital role in extending Moore's Law and enabling the development of high-performance and energy-efficient integrated circuits.