High-k double gate junctionless tunnel FET with a tunable bandgap

Abstract

In the present work, the performance of a heterostructure double gate junctionless tunnel FET (HJL-DGTFET) having a tunable source bandgap has been analyzed using a 2D simulation technique. The tunable source HJL-DGTFET shows a high ON-current (≈ 6.5 × 10⁻⁵ A μm⁻¹) and a very low OFF-current (≈ 4.8 × 10⁻¹⁷ A μm⁻¹). The device shows a point subthreshold slope ≈ 36.2 to 26.8 mV per decade and the average subthreshold slope ≈ 86.1 to 84.2 mV per decade for 0.0–40.0% Ge-mole fractions at room temperature with an I_ON/I_OFF ratio of 10¹². The excellent switching characteristics and steeper subthreshold slope at room temperature indicate that this is a promising candidate for the replacement of bulk MOSFETs. In this article, the optimization of device parameters such as the oxide thickness (t_ox), gate dielectric material and spacer has also been discussed in detail.