Extremely low temperature growth of ZnO by atomic layer deposition

We report on the zinc oxide (ZnO) thin films obtained by the atomic layer deposition (ALD) method using diethyl zinc and water precursors, which allowed us to lower deposition temperature to below 200 °C. The so-obtained “as grown” ZnO layers are polycrystalline and show excitonic photoluminescence (PL) at room temperature, even if the deposition temperature was lowered down to 100 °C. Defect-related PL bands are of low intensity and are absent for layers grown at 140−200 °C. This is evidence that extremely low temperature growth by ALD can result in high quality ZnO thin films with inefficient nonradiative decay channels and with thermodynamically blocked self-compensation processes.

[1]  C. Hwang,et al.  Comparison between ZnO films grown by atomic layer deposition using H2O or O3 as oxidant , 2005 .

[2]  D. C. Reynolds,et al.  Optically pumped ultraviolet lasing from ZnO , 1996 .

[3]  Ding-Yuan Chen,et al.  ZnO thin-film transistors with polycrystalline (Ba,Sr)TiO3 gate insulators , 2006 .

[4]  D. C. Reynolds,et al.  Production and annealing of electron irradiation damage in ZnO , 1999 .

[5]  R. McLean,et al.  Transparent ZnO thin-film transistor fabricated by rf magnetron sputtering , 2003 .

[6]  Chongmu Lee,et al.  Effects of substrate temperature on the microstructure and photoluminescence properties of ZnO thin films prepared by atomic layer deposition , 2007 .

[7]  K. Wong,et al.  Intensity dependence and transient dynamics of donor–acceptor pair recombination in ZnO thin films grown on (001) silicon , 2003 .

[8]  B. Meyer,et al.  The Oxygen Vacancy as the Origin of a Green Emission in Undoped ZnO , 2001 .

[9]  Pedro Barquinha,et al.  Wide-bandgap high-mobility ZnO thin-film transistors produced at room temperature , 2004 .

[10]  Hyoun-woo Kim,et al.  Photoluminescence Studies of ZnO thin films grown by atomic layer epitaxy , 2004 .

[11]  Bruno K. Meyer,et al.  Oxygen vacancies in ZnO , 2003 .

[12]  David P. Norton,et al.  Recent progress in processing and properties of ZnO , 2003 .

[13]  H. Morkoç,et al.  A COMPREHENSIVE REVIEW OF ZNO MATERIALS AND DEVICES , 2005 .

[14]  G. Ceder,et al.  First-principles study of native point defects in ZnO , 2000 .

[15]  Chung‐Chih Wu,et al.  Scaling behavior of ZnO transparent thin-film transistors , 2006 .

[16]  R. Street,et al.  Silicon-hydrogen bonding and hydrogen diffusion in amorphous silicon. , 1995, Physical review. B, Condensed matter.

[17]  Hongen Shen,et al.  High contrast, ultrafast optically addressed ultraviolet light modulator based upon optical anisotropy in ZnO films grown on R-plane sapphire , 1999 .

[18]  S. Studenikin,et al.  Fabrication of green and orange photoluminescent, undoped ZnO films using spray pyrolysis , 1998 .

[19]  E. Guziewicz,et al.  Low temperature growth of ZnMnO: A way to avoid inclusions of foreign phases and spinodal decomposition , 2007 .

[20]  Y. Su,et al.  Hydrogen-doped high conductivity ZnO films deposited by radio-frequency magnetron sputtering , 2004 .

[21]  Zhenan Bao,et al.  New Air-Stable n-Channel Organic Thin Film Transistors , 1998 .

[22]  William L. Warren,et al.  Green photoluminescence efficiency and free-carrier density in ZnO phosphor powders prepared by spray pyrolysis , 1997 .

[23]  H. C. Ong,et al.  Effect of post-thermal annealing on properties of ZnO thin film grown on c-Al2O3 by metal-organic chemical vapor deposition , 2003 .

[24]  Bruce E. Gnade,et al.  Mechanisms behind green photoluminescence in ZnO phosphor powders , 1996 .

[25]  S. Pearton,et al.  Zinc oxide bulk, thin films and nanostructures : processing, properties and applications , 2006 .

[26]  Hans-Joachim Egelhaaf,et al.  Luminescence and nonradiative deactivation of excited states involving oxygen defect centers in polycrystalline ZnO , 1996 .

[27]  E. Guziewicz,et al.  Magnetic properties of ZnMnO films grown at low temperature by atomic layer deposition , 2006 .

[28]  William L. Warren,et al.  Correlation between photoluminescence and oxygen vacancies in ZnO phosphors , 1996 .

[29]  Satoshi Masuda,et al.  Transparent thin film transistors using ZnO as an active channel layer and their electrical properties , 2003 .