In situ measurement of the internal stress evolution during sputter deposition of ZnO:Al

Transparent and conductive ZnO:Al films were deposited by RF magnetron sputtering on opaque (Si/SiO2) or transparent (glass) substrates. The internal stress evolution has been measured in situ using a high resolution 2D curvature measurement technique. Internal tensile or compressive stresses were generated, depending on the sputtering pressure, oxygen addition level and substrate temperature. The origin of the observed stress level is correlated with factors affecting the film growth mechanism, and the relation with the electro-optical properties of the resulting transparent and conductive oxide films is highlighted.