Low temperature growth and optical properties of α-Ga2O3 deposited on sapphire by plasma enhanced atomic layer deposition

Roberts, J.W. and Chalker, P.R. and Ding, B. and Oliver, R.A. and Gibbon, J.T. and Jones, L.A.H. and Dhanak, V.R. and Phillips, L.J. and Major, J.D. and Massabuau, F.C.-P. (2019) Low temperature growth and optical properties of α-Ga2O3 deposited on sapphire by plasma enhanced atomic layer deposition. Journal of Crystal Growth, 528. 125254. ISSN 0022-0248 (https://doi.org/10.1016/j.jcrysgro.2019.125254)

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Abstract

Plasma enhanced atomic layer deposition was used to deposit thin films of Ga2O3 on to c-plane sapphire substrates using triethylgallium and O2 plasma. The influence of substrate temperature and plasma processing parameters on the resultant crystallinity and optical properties of the Ga2O3 films were investigated. The deposition temperature was found to have a significant effect on the film crystallinity. At temperatures below 200°C amorphous Ga2O3 films were deposited. Between 250°C and 350°C the films became predominantly α-Ga2O3. Above 350°C the deposited films showed a mixture of α-Ga2O3 and ε-Ga2O3 phases. Plasma power and O2 flow rate were observed to have less influence over the resultant phases present in the films. However, both parameters could be tuned to alter the strain of the film. Ultraviolet transmittance measurements on the Ga2O3 films showed that the bandgaps ranges from 5.0 eV to 5.2 eV with the largest bandgap of 5.2 eV occurring for the α-Ga2O3 phase deposited at 250°C.

  • Item type:Article
    ID code:70036
    Dates:
    Date
    Event
    15 December 2019
    Published
    25 September 2019
    Published Online
    24 September 2019
    Accepted
    Subjects:Science > Physics
    Department:Faculty of Science > Physics
    Depositing user: Pure Administrator
    Date deposited:07 Oct 2019 11:24
    Last modified:17 Apr 2024 00:35
    Related URLs:
    URI:https://strathprints.strath.ac.uk/id/eprint/70036
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