Contacting mechanically exfoliated β-Ga2O3 nanobelts for (opto)electronic device applications

Jinho Bae, Hong Yeol Kim, Ji Hyun Kim

Research output: Contribution to journalArticle

8 Citations (Scopus)

Abstract

We systematically investigated the properties of metal contacts deposited on exfoliated β-Ga2O3 nanobelts. Unintentionally doped β-Ga2O3 was mechanically exfoliated from bulk β-Ga2O3 crystal and transferred onto SiO2/Si substrate having a back gate configuration. Electrodes were formed by depositing Ti/Au or Ni/Au onto the transferred β-Ga2O3 nanobelts, followed by rapid thermal annealing (RTA) with different ambient gases and temperatures. Using scanning transmission electron microscopy (STEM) and energy-dispersive X-ray spectroscopy (EDS), it was shown that titanium reacts with oxygen to form titanium oxide, which has ohmic behavior. In contrast, nickel does not form an ohmic contact despite 600°C thermal treatment. The lower oxygen partial pressure in a nitrogen atmosphere as compared to air results in more oxygen vacancies within the Ga2O3 nanobelts during RTA and a negative threshold voltage shift. A decreased current level after high temperature annealing can be ascribed to significant outward diffusion of oxygen and gallium atoms and to oxidation of the metal electrode. Our results can pave a route to demonstrating high performance β-Ga2O3 nanobelt-based (opto)electronic devices.

Original languageEnglish
Pages (from-to)Q3045-Q3048
JournalECS Journal of Solid State Science and Technology
Volume6
Issue number2
DOIs
Publication statusPublished - 2017

Fingerprint

Nanobelts
Optoelectronic devices
Rapid thermal annealing
Oxygen
Metals
Gallium
Electrodes
Ohmic contacts
Titanium oxides
Oxygen vacancies
Titanium
Nickel
Threshold voltage
Partial pressure
Energy dispersive spectroscopy
Nitrogen
Gases
Heat treatment
Annealing
Transmission electron microscopy

ASJC Scopus subject areas

  • Electronic, Optical and Magnetic Materials

Cite this

Contacting mechanically exfoliated β-Ga2O3 nanobelts for (opto)electronic device applications. / Bae, Jinho; Kim, Hong Yeol; Kim, Ji Hyun.

In: ECS Journal of Solid State Science and Technology, Vol. 6, No. 2, 2017, p. Q3045-Q3048.

Research output: Contribution to journalArticle

@article{8ffd6444e15c4d83af6b4c3af6b53664,
title = "Contacting mechanically exfoliated β-Ga2O3 nanobelts for (opto)electronic device applications",
abstract = "We systematically investigated the properties of metal contacts deposited on exfoliated β-Ga2O3 nanobelts. Unintentionally doped β-Ga2O3 was mechanically exfoliated from bulk β-Ga2O3 crystal and transferred onto SiO2/Si substrate having a back gate configuration. Electrodes were formed by depositing Ti/Au or Ni/Au onto the transferred β-Ga2O3 nanobelts, followed by rapid thermal annealing (RTA) with different ambient gases and temperatures. Using scanning transmission electron microscopy (STEM) and energy-dispersive X-ray spectroscopy (EDS), it was shown that titanium reacts with oxygen to form titanium oxide, which has ohmic behavior. In contrast, nickel does not form an ohmic contact despite 600°C thermal treatment. The lower oxygen partial pressure in a nitrogen atmosphere as compared to air results in more oxygen vacancies within the Ga2O3 nanobelts during RTA and a negative threshold voltage shift. A decreased current level after high temperature annealing can be ascribed to significant outward diffusion of oxygen and gallium atoms and to oxidation of the metal electrode. Our results can pave a route to demonstrating high performance β-Ga2O3 nanobelt-based (opto)electronic devices.",
author = "Jinho Bae and Kim, {Hong Yeol} and Kim, {Ji Hyun}",
year = "2017",
doi = "10.1149/2.0091702jss",
language = "English",
volume = "6",
pages = "Q3045--Q3048",
journal = "ECS Journal of Solid State Science and Technology",
issn = "2162-8769",
publisher = "Electrochemical Society, Inc.",
number = "2",

}

TY - JOUR

T1 - Contacting mechanically exfoliated β-Ga2O3 nanobelts for (opto)electronic device applications

AU - Bae, Jinho

AU - Kim, Hong Yeol

AU - Kim, Ji Hyun

PY - 2017

Y1 - 2017

N2 - We systematically investigated the properties of metal contacts deposited on exfoliated β-Ga2O3 nanobelts. Unintentionally doped β-Ga2O3 was mechanically exfoliated from bulk β-Ga2O3 crystal and transferred onto SiO2/Si substrate having a back gate configuration. Electrodes were formed by depositing Ti/Au or Ni/Au onto the transferred β-Ga2O3 nanobelts, followed by rapid thermal annealing (RTA) with different ambient gases and temperatures. Using scanning transmission electron microscopy (STEM) and energy-dispersive X-ray spectroscopy (EDS), it was shown that titanium reacts with oxygen to form titanium oxide, which has ohmic behavior. In contrast, nickel does not form an ohmic contact despite 600°C thermal treatment. The lower oxygen partial pressure in a nitrogen atmosphere as compared to air results in more oxygen vacancies within the Ga2O3 nanobelts during RTA and a negative threshold voltage shift. A decreased current level after high temperature annealing can be ascribed to significant outward diffusion of oxygen and gallium atoms and to oxidation of the metal electrode. Our results can pave a route to demonstrating high performance β-Ga2O3 nanobelt-based (opto)electronic devices.

AB - We systematically investigated the properties of metal contacts deposited on exfoliated β-Ga2O3 nanobelts. Unintentionally doped β-Ga2O3 was mechanically exfoliated from bulk β-Ga2O3 crystal and transferred onto SiO2/Si substrate having a back gate configuration. Electrodes were formed by depositing Ti/Au or Ni/Au onto the transferred β-Ga2O3 nanobelts, followed by rapid thermal annealing (RTA) with different ambient gases and temperatures. Using scanning transmission electron microscopy (STEM) and energy-dispersive X-ray spectroscopy (EDS), it was shown that titanium reacts with oxygen to form titanium oxide, which has ohmic behavior. In contrast, nickel does not form an ohmic contact despite 600°C thermal treatment. The lower oxygen partial pressure in a nitrogen atmosphere as compared to air results in more oxygen vacancies within the Ga2O3 nanobelts during RTA and a negative threshold voltage shift. A decreased current level after high temperature annealing can be ascribed to significant outward diffusion of oxygen and gallium atoms and to oxidation of the metal electrode. Our results can pave a route to demonstrating high performance β-Ga2O3 nanobelt-based (opto)electronic devices.

UR - http://www.scopus.com/inward/record.url?scp=85011422927&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=85011422927&partnerID=8YFLogxK

U2 - 10.1149/2.0091702jss

DO - 10.1149/2.0091702jss

M3 - Article

AN - SCOPUS:85011422927

VL - 6

SP - Q3045-Q3048

JO - ECS Journal of Solid State Science and Technology

JF - ECS Journal of Solid State Science and Technology

SN - 2162-8769

IS - 2

ER -