Origin of the Threshold Voltage Shift in a Transistor with a 2D Electron Gas Channel at the Al2O3/SrTiO3 Interface

Abstract A transistor is fabricated with a 2D electron gas (2DEG) channel at the Al2O3 (AO)/SrTiO3 (STO) interface. The threshold voltage (Vth) shift of the 2DEG channel in the Pt/AO/2DEG/STO stack induced by negative bias stress is investigated. Two‐terminal current–voltage and capacitance–voltage...

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Main Authors: Taehwan Moon, Hyun Jae Lee, Seung Dam Hyun, Baek Su Kim, Ho Hyun Kim, Cheol Seong Hwang
Format: Article
Language:English
Published: Wiley-VCH 2020-06-01
Series:Advanced Electronic Materials
Subjects:
Online Access:https://doi.org/10.1002/aelm.201901286
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author Taehwan Moon
Hyun Jae Lee
Seung Dam Hyun
Baek Su Kim
Ho Hyun Kim
Cheol Seong Hwang
author_facet Taehwan Moon
Hyun Jae Lee
Seung Dam Hyun
Baek Su Kim
Ho Hyun Kim
Cheol Seong Hwang
author_sort Taehwan Moon
collection DOAJ
description Abstract A transistor is fabricated with a 2D electron gas (2DEG) channel at the Al2O3 (AO)/SrTiO3 (STO) interface. The threshold voltage (Vth) shift of the 2DEG channel in the Pt/AO/2DEG/STO stack induced by negative bias stress is investigated. Two‐terminal current–voltage and capacitance–voltage characterization through the gate and the source reveals that the metallic 2DEG channel turns into a semiconducting channel when the negative bias stress is applied. Transfer curve measurement with various stress conditions on the 2DEG field‐effect transistor is performed to evaluate the effect of the negative bias stress. The Vth becomes positive, and the channel conductance decreases after the application of negative bias stress. These variations are promoted by large stress bias and temperature. Electron energy loss spectroscopy analysis via scanning transmission electron microscopy reveals that the chemical state of the interface changes from oxygen‐deficient to stoichiometric. Therefore, the change in the channel state from metallic to semiconducting originates from the decrease of oxygen vacancy concentration at the interface.
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spelling doaj-art-97ce2dbd47df464c977e4f3ad55897d52025-08-20T02:46:17ZengWiley-VCHAdvanced Electronic Materials2199-160X2020-06-0166n/an/a10.1002/aelm.201901286Origin of the Threshold Voltage Shift in a Transistor with a 2D Electron Gas Channel at the Al2O3/SrTiO3 InterfaceTaehwan Moon0Hyun Jae Lee1Seung Dam Hyun2Baek Su Kim3Ho Hyun Kim4Cheol Seong Hwang5Department of Materials Science and Engineering and Inter‐University Semiconductor Research Center Seoul National University Seoul 08826 Republic of KoreaDepartment of Materials Science and Engineering and Inter‐University Semiconductor Research Center Seoul National University Seoul 08826 Republic of KoreaDepartment of Materials Science and Engineering and Inter‐University Semiconductor Research Center Seoul National University Seoul 08826 Republic of KoreaDepartment of Materials Science and Engineering and Inter‐University Semiconductor Research Center Seoul National University Seoul 08826 Republic of KoreaDepartment of Materials Science and Engineering and Inter‐University Semiconductor Research Center Seoul National University Seoul 08826 Republic of KoreaDepartment of Materials Science and Engineering and Inter‐University Semiconductor Research Center Seoul National University Seoul 08826 Republic of KoreaAbstract A transistor is fabricated with a 2D electron gas (2DEG) channel at the Al2O3 (AO)/SrTiO3 (STO) interface. The threshold voltage (Vth) shift of the 2DEG channel in the Pt/AO/2DEG/STO stack induced by negative bias stress is investigated. Two‐terminal current–voltage and capacitance–voltage characterization through the gate and the source reveals that the metallic 2DEG channel turns into a semiconducting channel when the negative bias stress is applied. Transfer curve measurement with various stress conditions on the 2DEG field‐effect transistor is performed to evaluate the effect of the negative bias stress. The Vth becomes positive, and the channel conductance decreases after the application of negative bias stress. These variations are promoted by large stress bias and temperature. Electron energy loss spectroscopy analysis via scanning transmission electron microscopy reveals that the chemical state of the interface changes from oxygen‐deficient to stoichiometric. Therefore, the change in the channel state from metallic to semiconducting originates from the decrease of oxygen vacancy concentration at the interface.https://doi.org/10.1002/aelm.2019012862D electron gasSrTiO 3threshold voltagetransistors
spellingShingle Taehwan Moon
Hyun Jae Lee
Seung Dam Hyun
Baek Su Kim
Ho Hyun Kim
Cheol Seong Hwang
Origin of the Threshold Voltage Shift in a Transistor with a 2D Electron Gas Channel at the Al2O3/SrTiO3 Interface
Advanced Electronic Materials
2D electron gas
SrTiO 3
threshold voltage
transistors
title Origin of the Threshold Voltage Shift in a Transistor with a 2D Electron Gas Channel at the Al2O3/SrTiO3 Interface
title_full Origin of the Threshold Voltage Shift in a Transistor with a 2D Electron Gas Channel at the Al2O3/SrTiO3 Interface
title_fullStr Origin of the Threshold Voltage Shift in a Transistor with a 2D Electron Gas Channel at the Al2O3/SrTiO3 Interface
title_full_unstemmed Origin of the Threshold Voltage Shift in a Transistor with a 2D Electron Gas Channel at the Al2O3/SrTiO3 Interface
title_short Origin of the Threshold Voltage Shift in a Transistor with a 2D Electron Gas Channel at the Al2O3/SrTiO3 Interface
title_sort origin of the threshold voltage shift in a transistor with a 2d electron gas channel at the al2o3 srtio3 interface
topic 2D electron gas
SrTiO 3
threshold voltage
transistors
url https://doi.org/10.1002/aelm.201901286
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