• JSTS:Journal of Semiconductor Technology and Science
• /
• 제13권3호
• /
• pp.224-236
• /
• 2013

This work presents a comparative study of four Double Gate tunnel FET (DG-TFET) architectures: conventional p-i-n DG-TFET, p-n-p-n DG-TFET, a gate dielectric engineered Heterogate (HG) p-i-n DG-TFET and a new device architecture with the merits of both Hetero Gate and p-n-p-n, i.e. HG p-n-p-n DG-TFET. It has been shown that, the problem of high gate capacitance along with low ON current for a p-i-n TFET, which severely hampers the circuit performance of TFET can be overcome by using a p-n-p-n TFET with a dielectric engineered Hetero-gate architecture (i.e. HG p-n-p-n). P-n-p-n architecture improves the ON current and the heterogeneous dielectric helps in reducing the gate capacitance and suppressing the ambipolar behavior. Moreover, the HG architecture does not degrade the output characteristics, unlike the gate drain underlap architecture, and effectively reduces the gate capacitance.

• Journal of Electrical Engineering and Technology
• /
• 제9권6호
• /
• pp.2070-2078
• /
• 2014

In this work, the frequency response of gate-all-around (GAA) Ge/GaAs heterojunction tunneling field-effect transistor (TFET) with hetero-gate-dielectric (HGD) and pnpn channel doping profile has been analysed by technology computer-aided design (TCAD) device-circuit mixed-mode simulations, with comparison studies among ppn, pnpn, and HGD pnpn TFET devices. By recursive tracing of voltage transfer curves (VTCs) of a common-source (CS) amplifier based on the HGD pnpn TFET, the operation point (Q-point) was obtained at $V_{DS}=1V$, where the maximum available output swing was acquired without waveform distortion. The slope of VTC of the amplifier was 9.21 V/V (19.4 dB), which mainly resulted from the ponderable direct-current (DC) characteristics of HGD pnpn TFET. Along with the DC performances, frequency response with a small-signal voltage of 10 mV has been closely investigated in terms of voltage gain ($A_v$), unit-gain frequency ($f_{unity}$), and cut-off frequency ($f_T$). The Ge/GaAs HGD pnpn TFET demonstrated $A_v=19.4dB$, $f_{unity}=10THz$, $f_T=0.487$ THz and $f_{max}=18THz$.

• JSTS:Journal of Semiconductor Technology and Science
• /
• 제13권6호
• /
• pp.551-555
• /
• 2013

Linearity characteristics of hetero-gate-dielectric tunneling field-effect transistors (HG TFETs) have been compared with those of high-k-only and $SiO_2$-only TFETs in terms of IIP3 and P1dB. It has been observed that the optimized HG TFETs have higher IIP3 and P1dB than high-k-only and $SiO_2$-only TFETs. It is because HG TFETs show higher transconductance ($g_m$) and current drivability than $SiO_2$-only TFETs and $g_m$ less sensitive to gate voltage than high-k-only TFETs.