Design and Investigation of Ge Source Hetero-Dielectric L-Shaped TFET for Low Power Applications

This study explores a novel transistor design that combines a Germanium source with an L-shaped tunnel field-effect transistor (LTFET) structure, incorporating a Hetero-Gate- Dielectric (Ge- HD- LTFET). Simulations indicate that the Ge-Hd-LTfeT with a Si-Ge pocket region exhibits superior performance compared to the design without the pocket. This improvement is characterized by higher ON-current (I<inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">ON</inf>), lower OFF-current (I<inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">OFF</inf>), and a significantly reduced subthreshold swing (SS). The researchers analyzed various aspects of the transistor, including current-voltage characteristics, the distribution of band-to-band tunneling (BTBT) generation rate, electric field density, and the variation of material composition (mole fraction) within the pocket region. The findings reveal that the Ge-HD-LTfetwith the Si-Ge pocket achieves a higher ON current due to an increased cross-sectional area at the BTBT junction. Additionally, the implementation of the hetero-gate-dielectric effectively suppresses ambipolar current. Finally, the study investigates how changes in key device parameters influence the transistor's functionality, providing valuable insights for optimization.