Improvement of Electrical Characteristics of SiGe Source Based Tunnel FET Device

Tunnel Field Effect Transistor (TFET) is one of the most promising alternative device for semiconductor technology and shows better performance as compared to the conventional MOS device in terms of subthreshold swing, OFF current, etc. In this paper, SiGe source-based Heterojunction Tunnel FET has been investigated to enhance the performance of the device in terms of ON current and I-ON/I(OFF)ratio. The use of spacers has also been studied for enhancing the drain current. The combination of low-k (SiO2) and a high-k (HfO2) hetero dielectric material have been studied for the use of gate dielectric material as well as at the buried oxide layer. The proposed device offers an ON current of 0.537 mA/mu m and an OFF current of 14.4 fA/mu m, with an excellent I-ON/I(OFF)ratio of 3.72 x 10(10). The average subthreshold swing of 28.57 mV/decade has also been achieved, which makes the device steeper. The ambipolar currents have been suppressed and hence the electrical characteristics of the proposed device are improved. The validity of the proposed device has been done by using TCAD simulation tool.