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 language | English |
|---|---|
| Pages (from-to) | Q3045-Q3048 |
| Journal | ECS Journal of Solid State Science and Technology |
| Volume | 6 |
| Issue number | 2 |
| DOIs | |
| Publication status | Published - 2017 |
Fingerprint
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 journal › Article
}
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 -