Dual-Material Double-Gate Source-Pocket Tunnel Field Effect Transistor with Homogeneous Gate Dielectric: Computational Analysis of Structural and Material Parameters for Enhanced Performance
摘要
Dual-material double-gate tunnel field effect transistor (DMDG TFET) is a promising candidate for low-power, high-speed electronics due to enhanced electrostatic control and superior switching characteristics. Integrating a pocket region between the source and channel—doped oppositely to the source—further improves tunneling efficiency by modulating the electric field at the tunneling junction. This combined architecture, termed the DMDG source-pocket TFET (DMDG-SP TFET), achieves higher ON current and reduced subthreshold swing compared to conventional TFETs. Previous DMDG-SP TFET designs used heterojunction structures and heterogeneous gate dielectrics, composed of two stacked insulators to enhance tunneling modulation and gate control. However, such hetero-structures increase fabrication complexity and may degrade reliability due to material incompatibility. This work proposes a novel DMDG-SP TFET design that combines a dual-material double-gate and a source-pocket in a homojunction silicon-based structure, using a single homogeneous high-k gate dielectric. 2-D TCAD simulations performed in Silvaco ATLAS demonstrate that the inclusion of the source-pocket improves ON current by 6.7 × and reduces subthreshold swing by 1.7 × compared to pocket-less devices. Dual-material gates boost ON current by 45% and improve ON/OFF ratio by 59% compared to single-material gates. Detailed simulations analyze the effects of gate work functions, dielectric constant, doping profiles and lengths of different regions. The optimized device achieves an ON current of 3.16 × 10⁻4 A/µm, OFF current of 1.54 × 10⁻17 A/µm, ON/OFF ratio of 2.05 × 1013, and point subthreshold swing of 6.29 mV/decade. These findings offer critical insights for designing manufacturable, high-performance TFETs for next-generation low-power integrated circuits.