Effects of stress on the structure of indium-tin-oxide thin films grown by pulsed laser deposition

The effects of stress in pulsed laser deposited (PLD) indium-tin-oxide (ITO) films formed on glass substrate at 200 °C and oxygen pressures (Po2) ranging from 0.1 to 2.7 Pa are discussed. Grazing incidence X-ray diffraction (GIXRD) investigations of the ITO films show splitting of the diffraction peaks and significant changes in the lattice constants for films deposited at low Po2 and when the thickness of the films is larger than 150 nm. These features were due to intrinsic stress caused by the incidence of energetic particles on the substrate during growth. The splitting of the peaks only occurred in the bulk of the films, while near the surface, single peaks were evidenced, indicating the existence of two layers. No apparent splitting of the diffraction peaks or shifts in peak positions occurred in the ITO layers with thickness less than 100 nm. In spite of the presence of stress in the ITO films, resistivity less than 3 10, -4 Ωcm was obtained. © 2001 Kluwer Academic Publishers