Microstructure of sputter deposited tin doped indium oxide films with silver additive

The microstructure of silver-containing indium tin oxide (ITO) films, deposited by sequential reactive direct current (DC) magnetron sputtering of ITO and Ag, was investigated by transmission electron microscopy (TEM) with selected area electron diffraction, high resolution TEM, energy dispersive spectroscopy, and energy-filtering TEM (EFTEM). All films had a columnar structure with (222) texture. The silver additive did not alter the ITO grain orientation, even though the columnar size of the ITO grains was decreased slightly when the silver content was increased. Nanoparticles of silver, with sizes ranging from 2 to 5 nm, were distributed in layers, as demonstrated by EFTEM using the Ag M4,5 peak. The influence of the silver deposit on the microstructure and properties of the ITO films is discussed.