Junctionless Electric-Double-Layer MoS2 Field-Effect Transistor with a Sub-5 nm Thick Electrostatically Highly Doped Channel

Dae Young Jeon, Jimin Park, So Jeong Park, Gyu Tae Kim

Research output: Contribution to journalArticlepeer-review

1 Citation (Scopus)

Abstract

Junctionless transistors are suitable for sub-3 nm applications because of their extremely simple structure and high electrical performance, which compensate for short-channel effects. Two-dimensional semiconductor transition-metal dichalcogenide materials, such as MoS2, may also resolve technical and fundamental issues for Si-based technology. Here, we present the first junctionless electric-double-layer field-effect transistor with an electrostatically highly doped 5 nm thick MoS2 channel. A double-gated MoS2 transistor with an ionic-liquid top gate and a conventional bottom gate demonstrated good transfer characteristics with a 104 on-off current ratio, a 70 mV dec-1 subthreshold swing at a 0 V bottom-gate bias, and drain-current versus top-gate-voltage characteristics were shifted left significantly with increasing bottom-gate bias due to an electrostatically increased overall charge carrier concentration in the MoS2 channel. When a bottom-gate bias of 80 V was applied, a shoulder and two clear peak features were identified in the transconductance and its derivative, respectively; this outcome is typical of Si-based junctionless transistors. Furthermore, the decrease in electron mobility induced by a transverse electric field was reduced with increasing bottom-gate bias. Numerical simulations and analytical models were used to support these findings, which clarify the operation of junctionless MoS2 transistors with an electrostatically highly doped channel.

Original languageEnglish
Pages (from-to)8298-8304
Number of pages7
JournalACS Applied Materials and Interfaces
Volume15
Issue number6
DOIs
Publication statusPublished - 2023 Feb 15

Bibliographical note

Funding Information:
This work was supported by the National Research Foundation of Korea (NRF, 2017M3A7B4049167 and MSIT-CPS21081-100) and the Korea Institute of Science and Technology (KIST), Open Research Program.

Publisher Copyright:
© 2023 American Chemical Society.

Keywords

  • double-gated MoS transistor
  • electrostatically highly doped channel
  • ionic-liquid gate
  • junctionless transistors
  • reduced mobility degradation
  • shoulder feature in transconductance
  • two peaks in transconductance derivative
  • two-dimensional semiconductor transition-metal dichalcogenide

ASJC Scopus subject areas

  • General Materials Science

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