Ambipolar Current Reduction in SiGe Source Based Heterojunction Tunnel FET

The constraints in scaling conventional MOSFETs have sparked a growing interest in Tunnel Field-Effect Transistors (TFETs) as a viable option for low-power applications. This investigation explores the inhibition of ambipolar conduction in a heterojunction TFET utilizing a SiGe source. The suggested configuration features a high-k Hafnium oxide dielectric at the source-channel interface and a low-k SiO<inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</inf> dielectric at the drain-channel interface, aiming to enhance band-to-band tunneling and reduce leakage currents. A buried oxide layer contributes to the reduction of ambipolar conduction by depleting the drain region. The device exhibited improved ON current, decreased OFF current, and a better subthreshold swing through the application of Visual TCAD simulations. The molar concentration of SiGe was refined to 0.75 to achieve the optimal ON/OFF current ratio. The proposed design demonstrates superior performance when compared to conventional TFET architectures, positioning it as a promising candidate for future energy-efficient electronic devices.