Control of Schottky barrier height in metal/ β -Ga2O3 junctions by insertion of PdCoO2 layers

T. Harada; A. Tsukazaki

doi:10.1063/1.5145117

Control of Schottky barrier height in metal/ β -Ga₂O₃ junctions by insertion of PdCoO₂ layers

T. Harada, A. Tsukazaki

Materials Property Division

Research output: Contribution to journal › Article › peer-review

11 Citations (Scopus)

Abstract

Control of Schottky barrier heights (SBHs) at metal/semiconductor interfaces is a critically important technique to design switching properties of semiconductor devices. In this study, we report the systematic variations of SBHs in metal/PdCoO₂/β-Ga₂O₃ junctions with an increase in the thickness of the PdCoO₂ insertion layer. The PdCoO₂ insertion layer consists of ionic Pd⁺ and [CoO₂]^- sublattices alternatingly stacked along the normal of the Schottky interface. This polar layered structure of PdCoO₂ spontaneously induces interface dipoles that increase the SBH in β-Ga₂O₃ devices. We fabricated Schottky junctions composed of metal/PdCoO₂/β-Ga₂O₃ (-201) with the PdCoO₂ thickness of 0-20 nm. With an increase in the PdCoO₂ thickness, we observed a systematic shift of current density-voltage (J-V) characteristics to larger forward driving voltage. The shift of J-V characteristics indicates the enhancement of SBH by insertion of the PdCoO₂ layer, which was confirmed by the capacitance measurement as the consistent shift of the built-in potential. These results demonstrate a controllable SBH in a wide range of 0.7-1.9 eV driven by a decisive contribution of the interface dipole effect. The Schottky junctions based on β-Ga₂O₃ with variable barrier heights could fit a wide range of applications, with the significant merits of optimizable switching properties.

Original language	English
Article number	041109
Journal	APL Materials
Volume	8
Issue number	4
DOIs	https://doi.org/10.1063/1.5145117
Publication status	Published - 2020 Apr 1

ASJC Scopus subject areas

Materials Science(all)
Engineering(all)

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10.1063/1.5145117

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title = "Control of Schottky barrier height in metal/ β -Ga2O3 junctions by insertion of PdCoO2 layers",

abstract = "Control of Schottky barrier heights (SBHs) at metal/semiconductor interfaces is a critically important technique to design switching properties of semiconductor devices. In this study, we report the systematic variations of SBHs in metal/PdCoO2/β-Ga2O3 junctions with an increase in the thickness of the PdCoO2 insertion layer. The PdCoO2 insertion layer consists of ionic Pd+ and [CoO2]- sublattices alternatingly stacked along the normal of the Schottky interface. This polar layered structure of PdCoO2 spontaneously induces interface dipoles that increase the SBH in β-Ga2O3 devices. We fabricated Schottky junctions composed of metal/PdCoO2/β-Ga2O3 (-201) with the PdCoO2 thickness of 0-20 nm. With an increase in the PdCoO2 thickness, we observed a systematic shift of current density-voltage (J-V) characteristics to larger forward driving voltage. The shift of J-V characteristics indicates the enhancement of SBH by insertion of the PdCoO2 layer, which was confirmed by the capacitance measurement as the consistent shift of the built-in potential. These results demonstrate a controllable SBH in a wide range of 0.7-1.9 eV driven by a decisive contribution of the interface dipole effect. The Schottky junctions based on β-Ga2O3 with variable barrier heights could fit a wide range of applications, with the significant merits of optimizable switching properties.",

author = "T. Harada and A. Tsukazaki",

note = "Funding Information: The authors thank K. Fujiwara for the experimental help with sputtering and NEOARK Corporation for the use of a maskless lithography system PALET. This work was performed under the Inter-university Cooperative Research Program of the CRDAM-IMR, Tohoku University (Proposal No. 18G0407). This work was partly supported by a Grant-in-Aid for Scientific Research (A) (Grant No. 15H02022) and a Grant-in-Aid for Early-Career Scientists (Grant No. 18K14121) from the Japan Society for the Promotion of Science (JSPS), JST CREST (No. JPMJCR18T2). Publisher Copyright: {\textcopyright} 2020 Author(s).",

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T1 - Control of Schottky barrier height in metal/ β -Ga2O3 junctions by insertion of PdCoO2 layers

AU - Harada, T.

AU - Tsukazaki, A.

N1 - Funding Information: The authors thank K. Fujiwara for the experimental help with sputtering and NEOARK Corporation for the use of a maskless lithography system PALET. This work was performed under the Inter-university Cooperative Research Program of the CRDAM-IMR, Tohoku University (Proposal No. 18G0407). This work was partly supported by a Grant-in-Aid for Scientific Research (A) (Grant No. 15H02022) and a Grant-in-Aid for Early-Career Scientists (Grant No. 18K14121) from the Japan Society for the Promotion of Science (JSPS), JST CREST (No. JPMJCR18T2). Publisher Copyright: © 2020 Author(s).

PY - 2020/4/1

Y1 - 2020/4/1

N2 - Control of Schottky barrier heights (SBHs) at metal/semiconductor interfaces is a critically important technique to design switching properties of semiconductor devices. In this study, we report the systematic variations of SBHs in metal/PdCoO2/β-Ga2O3 junctions with an increase in the thickness of the PdCoO2 insertion layer. The PdCoO2 insertion layer consists of ionic Pd+ and [CoO2]- sublattices alternatingly stacked along the normal of the Schottky interface. This polar layered structure of PdCoO2 spontaneously induces interface dipoles that increase the SBH in β-Ga2O3 devices. We fabricated Schottky junctions composed of metal/PdCoO2/β-Ga2O3 (-201) with the PdCoO2 thickness of 0-20 nm. With an increase in the PdCoO2 thickness, we observed a systematic shift of current density-voltage (J-V) characteristics to larger forward driving voltage. The shift of J-V characteristics indicates the enhancement of SBH by insertion of the PdCoO2 layer, which was confirmed by the capacitance measurement as the consistent shift of the built-in potential. These results demonstrate a controllable SBH in a wide range of 0.7-1.9 eV driven by a decisive contribution of the interface dipole effect. The Schottky junctions based on β-Ga2O3 with variable barrier heights could fit a wide range of applications, with the significant merits of optimizable switching properties.

AB - Control of Schottky barrier heights (SBHs) at metal/semiconductor interfaces is a critically important technique to design switching properties of semiconductor devices. In this study, we report the systematic variations of SBHs in metal/PdCoO2/β-Ga2O3 junctions with an increase in the thickness of the PdCoO2 insertion layer. The PdCoO2 insertion layer consists of ionic Pd+ and [CoO2]- sublattices alternatingly stacked along the normal of the Schottky interface. This polar layered structure of PdCoO2 spontaneously induces interface dipoles that increase the SBH in β-Ga2O3 devices. We fabricated Schottky junctions composed of metal/PdCoO2/β-Ga2O3 (-201) with the PdCoO2 thickness of 0-20 nm. With an increase in the PdCoO2 thickness, we observed a systematic shift of current density-voltage (J-V) characteristics to larger forward driving voltage. The shift of J-V characteristics indicates the enhancement of SBH by insertion of the PdCoO2 layer, which was confirmed by the capacitance measurement as the consistent shift of the built-in potential. These results demonstrate a controllable SBH in a wide range of 0.7-1.9 eV driven by a decisive contribution of the interface dipole effect. The Schottky junctions based on β-Ga2O3 with variable barrier heights could fit a wide range of applications, with the significant merits of optimizable switching properties.

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ER -

Control of Schottky barrier height in metal/ β -Ga₂O₃ junctions by insertion of PdCoO₂ layers

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