Reconfigurable signal modulation in a ferroelectric tunnel field-effect transistor

Abstract

Reconfigurable transistors are an emerging device technology adding new functionalities while lowering the circuit architecture complexity. However, most investigations focus on digital applications. Here, we demonstrate a single vertical nanowire ferroelectric tunnel field-effect transistor (ferro-TFET) that can modulate an input signal with diverse modes including signal transmission, phase shift, frequency doubling, and mixing with significant suppression of undesired harmonics for reconfigurable analogue applications. We realize this by a heterostructure design in which a gate/source overlapped channel enables nearly perfect parabolic transfer characteristics with robust negative transconductance. By using a ferroelectric gate oxide, our ferro-TFET is non-volatilely reconfigurable, enabling various modes of signal modulation. The ferro-TFET shows merits of reconfigurability, reduced footprint, and low supply voltage for signal modulation. This work provides the possibility for monolithic integration of both steep-slope TFETs and reconfigurable ferro-TFETs towards high-density, energy-efficient, and multifunctional digital/analogue hybrid circuits.

Anti‐Ambipolar Heterojunctions: Materials, Devices, and Circuits

“…In 2023, vertical gate‐all‐around tunnel nanowire FETs were built with a ferroelectric Zr‐doped HfO 2 (HZO) insulting layer wrapping on an III‐V nanowire ( Figure a–c). [ 97,147 ] The vertical nanowire device exhibited a remarkable reduction in device footprint (≈0.01 µm 2 ) and supply voltage (as low as 50 mV). [ 148 ] With proper doping concentrations, the n‐doped InAs/intrinsic InAs/p‐doped (In)GaAsSb junction showed NDT behaviors (Figure 9d), while the carrier transport is dominated by the band‐to‐band tunneling process (Figure 9e).…”

“…More importantly, the presence of ferroelectricity in the HZO insulating layer allows for reconfigurable NDT behaviors in the vertical nanowire ferroelectric FETs, including a PVR ≈10 2 and a high symmetry AATs transfer curve. [ 97,149 ] After that, signal modulation circuits were also constructed based on reconfigurable vertical nanowire AATs to demonstrate different frequency multiplication, shifting, and mixing functions. This study showcases the potential of integrating high‐density vertical nanowire AATs into energy‐efficient, multifunctional digital/analog hybrid circuits.…”

“…c) Schematic illustration, d) anti‐ambipolar NDT behaviors, and e) schematic band diagrams under different gate voltages of vertical nanowire ferroelectric AATs. [ 97 ] a–e) Reproduced with permission. [ 97 ] Copyright 2023, Springer Nature.…”

“…A critical characteristic of AATs is their ability to exhibit both positive and negative transconductances, which can be effectively utilized in analog signal modulation circuits, including frequency doubling, phase shifting, and frequency mixing. [ 97 ]…”

“…Most recently, in 2023, a frequency mixer based on reconfigurable vertical nanowire tunnel FET was reported by Zhu et al., [ 97 ] by which two‐analog‐signal frequency mixing is performed on two input signals with f 1 = 1 kHz and f 2 = 800 Hz. The mixing power spectrum shown in Figure 17d reveals that a significant portion of output power (≈90%) is concentrated at frequencies f 1 ‐ f 2 and f 1 + f 2 .…”