Effects of O2plasma post-treatment on ZnO: Ga thin films grown by H2O-thermal ALD

Abstract

Transparent conducting oxides have been widely employed in optoelectronic devices using the various deposition methods such as sputtering, thermal evaporator, and e-gun evaporator technologies. 1-3 In this work, gallium doped zinc oxide (ZnO:Ga) thin films were grown on glass substrates via H 2 O-thermal atomic layer deposition (ALD) at different deposition temperatures. ALD-GZO thin films were constituted as a layer-by-layer structure by stacking zinc oxides and gallium oxides. Diethylzinc (DEZ), triethylgallium (TEG) and H 2 O were used as zinc, gallium precursors and oxygen source, respectively. Furthermore, we investigated the influences of O 2 plasma post-treatment power on the surface morphology, electrical and optical property of ZnO:Ga films. As the result of O 2 plasma post-treatment, the characteristics of ZnO:Ga films exhibit a smooth surface, low resistivity, high carrier concentration, and high optical transmittance in the visible spectrum. However, the transmittance decreases with O 2 plasma power in the near- and mid-infrared regions.