Quantitative study of the thickness-dependent stress in indium tin oxide thin films

A quantitative analysis of stress in indium tin oxide (ITO) films with varying thicknesses was conducted using high-precision stylus profilometry. The experimental results revealed a transition of the stress type from tensile to compressive as the ITO film thickness increased. Further investigation of the surface morphology of the ITO films indicated that the tensile stress originated from the impingement and coalescence of newly deposited equiaxed grains, while the observed compressive stress was attributed to the incorporation of excess material in the boundaries of columnar grains. The ability to monitor stress evolution in sputtered ITO films on glass substrates provides valuable insights for process control in ITO device manufacturing.