Investigation of Si1-XGeX source dual material stacked gate oxide pocket doped hetero-junction TFET for low power and RF applications

In this paper, the applicability of dual material stacked gate-oxide Pocket doped-hetero-junction tunnel field effect transistor (DMSGO-PD-HTFET) for low power switching and radio frequency (RF) applications is investigated. In this context, gate workfunction engineering, the stacked-gate-oxide (SiO2+HfO2) approach, and asymmetrical doping at the P+ source (Si1_XGeX) and N+ drain regions are considered. N+ pocket at source-channel interface implements DMSGO-PD-HTFET and improves interband tunnelling rate. This research aims to improve the device's switching ratio (ION/IOFF), average subthreshold swing (SSAvg), and radio frequency (RF) performance. For this, the control gate work function, mole fraction (X), pocket thickness, and doping concentration are optimised. Next, the DC, analog/RF and linearity figure of merits of the proposed device is analysed and the performance is compared with conventional all-silicon dual-material stack gate oxide tunnel field effect transistor (DMSGO-TFET) and dual-material stacked gate oxide-hetero-junction tunnel field effect transistor (DMSGOHTFET) with Si1_XGeX source using technology computer-aided design (TCAD) device simulator. Based on the comparative analysis, the optimised design with Si0:6Ge0:4 exhibits an average subthreshold swing (SSAvg) of 28.8 mV/decade, switching ratio (I-ON/I-OFF) of 2 x 10(12), cut-off frequency (f(T)) of 216 (GHz), and other significant improvements in analog/RF and linearity performance parameters. The proposed device is therefore suitable for switching and RF applications.