Ozone oxidation methods for aluminium oxide formation: application to low-voltage organic transistors

S. Gupta, S. Hannah, C. P. Watson , P. Sutta , R. H. Pedersen , N. Gadegaard , H. Gleskova

Research output: Contribution to journalArticle

10 Citations (Scopus)

Abstract

Four atmospheric pressure ozone oxidation methods were used to produce ultra-thin layers of aluminium oxide for organic thin-film transistors. They are UV/ozone oxidation in ambient (UV-AA) and dry (UV-DA) air, UV/ozone oxidation combined with high-voltage discharge-generated ozone in dry air (UV+O3-DA), and discharge-generated ozone in dry air (O3-DA). The lack of the high-energy UV photons during the O3-DA oxidation led to low relative permittivity and high leakage current density of the AlOx layer that rendered this method unsuitable for transistor dielectrics. Although this oxidation method led to the incorporation of oxygen into the film, the FTIR confirmed an increased concentration of the subsurface oxygen while the XPS showed the highest portion of the unoxidized Al among all four methods. The remaining three oxidation methods produced AlOx films with thicknesses in excess of 7 nm (2-hour oxidation time), relative permittivity between 6.61 and 7.25, and leakage current density of (1-7)x10-7 A/cm2 at 2 MV/cm, and were successfully implemented into organic thin-film transistors based on pentacene and DNTT. The presence of –OH groups in all oxides is below the detection limit, while some carbon impurities appear to be incorporated.
LanguageEnglish
Pages132-137
Number of pages6
JournalOrganic Electronics
Volume21
Early online date9 Mar 2015
DOIs
Publication statusPublished - 30 Jun 2015

Fingerprint

Aluminum Oxide
Ozone
low voltage
ozone
Transistors
transistors
aluminum oxides
Aluminum
Oxidation
oxidation
Oxides
Electric potential
Thin film transistors
Leakage currents
Discharge (fluid mechanics)
air
leakage
Permittivity
Current density
Air

Keywords

  • ozone oxidation
  • aluminium oxide
  • thin-film transistors
  • FTIR
  • XPS

Cite this

Gupta, S. ; Hannah, S. ; Watson , C. P. ; Sutta , P. ; Pedersen , R. H. ; Gadegaard , N. ; Gleskova, H. / Ozone oxidation methods for aluminium oxide formation : application to low-voltage organic transistors. In: Organic Electronics. 2015 ; Vol. 21. pp. 132-137.
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abstract = "Four atmospheric pressure ozone oxidation methods were used to produce ultra-thin layers of aluminium oxide for organic thin-film transistors. They are UV/ozone oxidation in ambient (UV-AA) and dry (UV-DA) air, UV/ozone oxidation combined with high-voltage discharge-generated ozone in dry air (UV+O3-DA), and discharge-generated ozone in dry air (O3-DA). The lack of the high-energy UV photons during the O3-DA oxidation led to low relative permittivity and high leakage current density of the AlOx layer that rendered this method unsuitable for transistor dielectrics. Although this oxidation method led to the incorporation of oxygen into the film, the FTIR confirmed an increased concentration of the subsurface oxygen while the XPS showed the highest portion of the unoxidized Al among all four methods. The remaining three oxidation methods produced AlOx films with thicknesses in excess of 7 nm (2-hour oxidation time), relative permittivity between 6.61 and 7.25, and leakage current density of (1-7)x10-7 A/cm2 at 2 MV/cm, and were successfully implemented into organic thin-film transistors based on pentacene and DNTT. The presence of –OH groups in all oxides is below the detection limit, while some carbon impurities appear to be incorporated.",
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Ozone oxidation methods for aluminium oxide formation : application to low-voltage organic transistors. / Gupta, S.; Hannah, S.; Watson , C. P.; Sutta , P.; Pedersen , R. H. ; Gadegaard , N.; Gleskova, H.

In: Organic Electronics, Vol. 21, 30.06.2015, p. 132-137.

Research output: Contribution to journalArticle

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