Reduction of Threshold Voltage Hysteresis of MoS2 Transistors with 3-Aminopropyltriethoxysilane Passivation and Its Application for Improved Synaptic Behavior

Kyu Hyun Han, Gwang Sik Kim, June Park, Seung Geun Kim, Jin Hong Park, Hyun Yong Yu

Research output: Contribution to journalArticlepeer-review

18 Citations (Scopus)

Abstract

Although molybdenum disulfide (MoS2) is highlighted as a promising channel material, MoS2-based field-effect transistors (FETs) have a large threshold voltage hysteresis (ΔVTH) from interface traps at their gate interfaces. In this work, the ΔVTH of MoS2 FETs is significantly reduced by inserting a 3-aminopropyltriethoxysilane (APTES) passivation layer at the MoS2/SiO2 gate interface owing to passivation of the interface traps. The ΔVTH is reduced from 23 to 10.8 V by inserting the 1%-APTES passivation layers because APTES passivation prevents trapping and detrapping of electrons, which are the major source of the ΔVTH. The reduction in the density of interface traps (Dit) is confirmed by the improvement of the subthreshold swing (SS) after inserting the APTES layer. Furthermore, the improvement in the synaptic characteristics of the MoS2 FET through the APTES passivation is investigated. Both inhibitory and excitatory postsynaptic currents (PSC) are increased by 33% owing to the reduction in the ΔVTH and the n-type doping effect of the APTES layer; moreover, the linearity of PSC characteristics is significantly improved because the reduction in ΔVTH enables the synaptic operation to be over the threshold region, which is linear. The application of the APTES gate passivation technique to MoS2 FETs is promising for reliable and accurate synaptic applications in neuromorphic computing technology as well as for the next-generation complementary logic applications.

Original languageEnglish
Pages (from-to)20949-20955
Number of pages7
JournalACS Applied Materials and Interfaces
Volume11
Issue number23
DOIs
Publication statusPublished - 2019 Jun 12

Bibliographical note

Funding Information:
This work was supported in part by the Basic Science Research Program within the Ministry of Science, ICT, and Future Planning through the National Research Foundation of Korea under grant 2017R1A2B4006460, in part by Nano Material Technology Development Program through the National Research Foundation of Korea (NRF) funded by the Ministry of Science, ICT and Future Planning (2016M3A7B4910426), and in part by the Nano Material Technology Development Program through the National Research Foundation of Korea funded by the Ministry of Science, ICT and Future Planning under grant 2015M3A7B7045490.

Publisher Copyright:
© 2019 American Chemical Society.

Keywords

  • 3-aminopropyltriethoxysilane
  • molybdenum disulfide
  • surface passivation
  • synapse applications
  • threshold voltage hysteresis

ASJC Scopus subject areas

  • General Materials Science

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