josefe

• Ellingsen, Josef Gert Åsheim; Venkatachalapathy, Vishnukanthan; Azarov, Alexander; Nilsen, Ola & Kuznetsov, Andrej (2020). Al incorporation during metal organic chemical vapour deposition of aluminium zinc oxide. Thin Solid Films. ISSN 0040-6090. 709. doi: 10.1016/j.tsf.2020.138245. Full text in Research Archive Show summary

  Aluminium zinc oxide (AZO) is a promising transparent conductive oxide this is difficult to fabricate by metal-organic chemical vapour deposition (MOCVD) because of prereactions between the precursors for Al and oxygen. One way of reducing prereactions is to use separate injectors. In this work, we investigated the effect of separate injectors and various flow configurations on the MOCVD fabrication of AZO using diethyl zinc (DEZn), tert-butanol (tBuOH), and trimethyl aluminium (TMAl) precursors. X-ray diffraction revealed that the resulting films maintained a purely wurtzite ZnO structure, and that the Al incorporation changed the c lattice parameters from 5.207 to 5.181 Å in agreement with theoretical models of mixing on the Zn sub-lattice. This indicates that Al was mainly incorporated onto the Zn sub-lattice. The maximum Al concentration was 6 × 1021 cm . The Al concentration was directly influenced by the TMAl flow rates, but the incorporation efficiency of Al also depended on the O/Zn balance as determined by the tBuOH supply and the total flow rate through the TMAl+DEZn injector. The tBuOH supply decreased the incorporation efficiency, while it increased for higher total flow in the TMAl+DEZn injector although both changes nominally increases the O/Zn balance. This dual, but contradicting, dependency on the O/Zn suggested that the incorporation efficiency depended not only on precursor supply, but also on the chemical stability of the Al species present at the growth interface. The concept of a reaction depth of TMAl was introduced to discuss the observed trends, and a qualitative model was suggested to explain how the Al-species present at the growth interface are determined by the relative depths of the reaction depth and the boundary layer. These findings illustrate the limits of the O/Zn parameter when using separate injectors because the properties of the boundary layer can affect Al incorporation during MOCVD growth. This should be relevant for MOCVD growth of other compound semiconductor systems that are grown using separate injectors.

• Azarov, Alexander; Galeckas, Augustinas; Wendler, Elke; Ellingsen, Josef Gert Åsheim; Monakhov, Edouard & Svensson, Bengt Gunnar (2017). Normal and reverse defect annealing in ion implanted II-VI oxide semiconductors. Journal of Applied Physics. ISSN 0021-8979. 122, p. 115701–115701. doi: 10.1063/1.4997847. Full text in Research Archive

View all works in NVA

• Frodason, Ymir Kalmann; Bergum, Kristin; Sky, Thomas Neset; Ingebrigtsen, Mads Eide; Borgersen, Jon & Ellingsen, Josef Gert Åsheim [Show all 8 contributors for this article] (2017). MiNa-Lab tour highlighting LENS activities. Full text in Research Archive
• Bergum, Kristin; Borgersen, Jon Arthur; Ellingsen, Josef Gert Åsheim; Hallén, Anders; Ingebrigtsen, Mads Eide & Kuznetsov, Andrej (2017). Omvisning MiNaLab, Slemdal skole 4. trinn. Full text in Research Archive
• Bergum, Kristin; Borgersen, Jon Arthur; Ellingsen, Josef Gert Åsheim; Frodason, Ymir Kalmann; Galeckas, Augustinas & Ingebrigtsen, Mads Eide [Show all 8 contributors for this article] (2017). Omvisning MiNaLab. Full text in Research Archive
• Bathen, Marianne Etzelmüller; Bergum, Kristin; Ellingsen, Josef Gert Åsheim; Grini, Sigbjørn; Sky, Thomas Neset & Aarseth, Bjørn Brevig (2017). Omvisning for Arendal VGS. Full text in Research Archive

View all works in NVA