Moisture-resistant ZnO transparent conductive films with Ga heavy doping

Moisture-resistant ZnO transparent conductive films were formed with Ga heavy doping by off-axis-type rf magnetron sputtering. The resistivity of 12.4 wt % Ga-doped ZnO is 1.3x10(-3) Omega cm and changes by less than 3% over a 2000 h reliability test at a temperature of 85 degrees C and a humidity of 85%. The crystal structural analysis of the heavily Ga-doped ZnO films indicates that the c axis grows along various directions, which is quite different from the conventional c-axis oriented growth. The effect of heavy doping is discussed based on the crystal structural transformation and carrier compensation by excess Ga segregated in the film. (c) 2006 American Institute of Physics.