Thin Solid Films, Vol.516, No.7, 1461-1463, 2008
Growth and characterisation of CaCu2Ox thin films by pulsed injection MOCVD
Oxides with the structure MCu2O2 (M = Ca, Ba, Mg and Sr) are promising materials for the development of new p-type transparent conducting oxide thin films. This paper reports preliminary results on the growth and characterisation of CaCu2Ox, thin films by pulsed injection MOCVD. By using as precursors calcium and copper tetramethytheptanedionate dissolved in meta-xylene, mixed calcium-copper films have been grown in the temperature range from 450 degrees C to 550 degrees C. At these temperatures, deposited films exhibited a high mirror reflection effect, good adherence and were reasonably uniform with the cationic composition of the films being easily controlled by adjusting the copper-calcium ratio in the precursor solution. In CaCu2O2, copper is in the Cu1+ oxidation state and depending on the oxygen partial pressure used, the films either contained CaCu2O3 or a mixture of CaO, CuO and Cu2O. Optimisation of annealing conditions increased the presence of Cu1+ in the film. Films had a maximum transmittance of 50% in the visible range and were highly resistive. Appropriate annealing conditions reduced the resistivity of the films. (C) 2007 Elsevier B.V. All rights reserved.