TY - JOUR
T1 - Atomic layer deposition of Al-doped ZnO films using ozone as the oxygen source
T2 - A comparison of two methods to deliver aluminum
AU - Yuan, Hai
AU - Luo, Bing
AU - Yu, Dan
AU - Cheng, An Jen
AU - Campbell, Stephen A.
AU - Gladfelter, Wayne L.
N1 - Funding Information:
This work was funded in part by a grant from the National Science Foundation Materials World Network under Award No. DMR-0908629. H.Y. is grateful for the fellowship support from the China Scholarship Council (CSC).
PY - 2012/1
Y1 - 2012/1
N2 - Aluminum-doped ZnO films were prepared by atomic layer deposition at 250C using diethylzinc (DEZ), trimethylaluminum (TMA), and ozone as the precursors. Two deposition methods were compared to assess their impact on the composition, structural, electrical, and optical properties as a function of Al concentration. The first method controlled the Al concentration by changing the relative number of Al to Zn deposition cycles; a process reported in the literature where water was used as the oxygen source. The second method involved coinjection of the DEZ and TMA during each cycle where the partial pressures of the precursors control the aluminum concentration. Depth profiles of the film composition using Auger electron spectroscopy confirmed a layered microstructure for the films prepared by the first method, whereas the second method led to a homogeneous distribution of the aluminum throughout the ZnO film. Beneath the surface layer the carbon concentrations for all of the films were below the detection limit. Comparison of their electrical and optical properties established that films deposited by coinjection of the precursors were superior.
AB - Aluminum-doped ZnO films were prepared by atomic layer deposition at 250C using diethylzinc (DEZ), trimethylaluminum (TMA), and ozone as the precursors. Two deposition methods were compared to assess their impact on the composition, structural, electrical, and optical properties as a function of Al concentration. The first method controlled the Al concentration by changing the relative number of Al to Zn deposition cycles; a process reported in the literature where water was used as the oxygen source. The second method involved coinjection of the DEZ and TMA during each cycle where the partial pressures of the precursors control the aluminum concentration. Depth profiles of the film composition using Auger electron spectroscopy confirmed a layered microstructure for the films prepared by the first method, whereas the second method led to a homogeneous distribution of the aluminum throughout the ZnO film. Beneath the surface layer the carbon concentrations for all of the films were below the detection limit. Comparison of their electrical and optical properties established that films deposited by coinjection of the precursors were superior.
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U2 - 10.1116/1.3666030
DO - 10.1116/1.3666030
M3 - Article
AN - SCOPUS:84855604777
SN - 0734-2101
VL - 30
JO - Journal of Vacuum Science and Technology A: Vacuum, Surfaces and Films
JF - Journal of Vacuum Science and Technology A: Vacuum, Surfaces and Films
IS - 1
M1 - 01A138
ER -