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 ($$Si{O_2}$$ Si O 2 + $$Hf{O_2}$$ Hf O 2 ) approach, and asymmetrical doping at the P+ source ($$S{i_{1 - X}}G{e_X}$$ S i 1 − X G e X ) 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 ($${I_{ON}}$$ I ON / $${I_{OFF}}$$ I OFF ), average subthreshold swing ($$S{S_{Avg}}$$ S S Avg ), 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 (DMSGO-HTFET) with $$S{i_{1 - X}}G{e_X}$$ S i 1 − X G e X source using technology computer-aided design (TCAD) device simulator. Based on the comparative analysis, the optimised design with $$S{i_{0.6}}G{e_{0.4}}$$ S i 0.6 G e 0.4 exhibits an average subthreshold swing ($$S{S_{Avg}}$$ S S Avg ) of 28.8 mV/decade, switching ratio ($${I_{ON}}$$ I ON / $${I_{OFF}}$$ I OFF ) of 2 × 1012, cut-off frequency ($${f_T}$$ 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. [ABSTRACT FROM AUTHOR]