High performance tunnel field-effect transistor by gate and source engineering.

Area of Science:

• Nanotechnology
• Solid-state physics
• Semiconductor device physics

Background:

• Tunnel field-effect transistors (TFETs) are promising for overcoming MOSFET subthreshold slope limitations.
• Achieving high ON-current, low OFF-current, and steep switching simultaneously in experimental TFETs remains challenging.
• Existing TFET designs struggle to balance performance metrics without compromising device area.

Purpose of the Study:

• To propose and experimentally demonstrate a novel multi-finger-gate TFET with a dopant-segregated Schottky source (mFSB-TFET).
• To investigate the performance enhancements offered by optimized gate configuration and Schottky junction in TFETs.
• To achieve steep switching characteristics and high ON/OFF current ratios in TFET devices.

Main Methods:

• Development of a new nanodevice technology based on TFET concepts.
• Design of a multi-finger-gate configuration with an optimized Schottky junction.
• Fabrication of the proposed mFSB-TFET on a bulk Silicon substrate and subsequent optimization using compatible SOI CMOS technology.

Main Results:

• The fabricated mFSB-TFET demonstrated a steeper subthreshold slope (SS) due to coupled quantum band-to-band tunneling (BTBT).
• A high ON/OFF current ratio (ION/IOFF) of approximately 10^7 was achieved at VDS = 0.2 V without an area penalty.
• Further optimization using SOI CMOS technology yielded an ION/IOFF ratio of ~10^8 and SS below 60 mV/decade, confirming dominant quantum BTBT.

Conclusions:

• The proposed mFSB-TFET design effectively addresses the limitations of conventional TFETs.
• The device exhibits excellent switching characteristics, including a steep SS and high ION/IOFF ratio, crucial for low-power nanoelectronics.
• The demonstrated performance highlights the potential of this TFET architecture for future nanoelectronic applications.