Atomic layer deposition and characterization of Ga-doped ZnO thin films

Low-resistivity n-type ZnO thin films were grown by atomic layer deposition (ALD) using diethylzinc (DEZ) and H2O as Zn and 0 precursors. ZnO thin films were grown on c-plane sapphire (C-Al2O3) substrates at 300 degrees C. For undoped ZnO thin films, it was found that the intensity of ZnO (10 (1) over bar1) reflection peak increased and the electron concentration increased from 6.8 x 10(18) to 1.1 x 10(20) cm(-3) with the increase of DEZ flow rate, which indicates the increase of 0 vacancies (V-O) and/or Zn interstitials (Zni). Ga-doping was performed under Zn-rich growth conditions using triethylgallium (TEG) as Ga precursor. The resistivity of 8.0 x 10(-4) Omega cm was achieved at the TEG flow rate of 0.24 mu mol/min. (c) 2007 Elsevier Ltd. All rights reserved.