Analysis of Negative Capacitance Source Pocket Double-Gate TFET with Steep Subthreshold and High ON–OFF Ratio

This article presents a study on the subthreshold swing (SS) and the ON–OFF current ratio of a negative capacitance source pocket double-gate tunnel field-effect transistor (NC-SP-DGTFET). In this analysis, a novel device is developed that integrates gate and channel engineering techniques. The combination of the ferroelectric material hafnium zirconium oxide (HZO) with the dielectric material SiO₂ generates a negative capacitance (NC) effect. Additionally, the incorporation of a totally depleted source pocket into the DGTFET reduces the tunneling width. The addition of NC has the potential to improve the SS through the amplification of the electric field at the tunnel junction. Moreover, it has been observed that a fully depleted source pocket within the source/channel region significantly enhances the I_ON current when compared to the double-gate tunnel field-effect transistor (DGTFET). Following thorough device optimization, there has been a notable enhancement in the I_ON/I_OFF current ratio, SS, and transconductance (g_m) by a factor of 1.54 × 10¹³, 20.8 mV/dec, and 5.102 × 10⁻⁴ S/µm, respectively. These improvements signify superior energy efficiency and enhanced performance when compared to both DGTFET and source pocket based DGTFET (SP-DGTFET) configurations. Furthermore, substantial research has been conducted on the variation in electrical properties in relation to the thickness of ferroelectric materials. The findings indicate that the proposed device exhibits considerable potential as a viable option for applications requiring both low power consumption and high operational speed.