Integration of high-k perovskite capacitor on transparent conductive Zr-doped In2O3 epitaxial thin films

SrTiO3 (STO) high-k thin films with various thicknesses (80–240 nm) were deposited on the epitaxial Zr-doped In2O3 electrodes. X-ray diffraction (XRD) results demonstrate that the STO films grown on the Zr-doped In2O3/Al2O3 substrates have a pure perovskite phase. The grain size of the STO film increases with film thickness as evaluated from the XRD rocking curves. The secondary ion mass spectrometer depth profiles reveal that an atomic interdiffusion between the constituent layers occurs at the STO/Zr-doped In2O3 heterointerface. The dielectric constant of the STO film decreases with decreasing the STO film thickness, owing to the low dielectric constant of the atomic intermixing interfacial layer. Moreover, the interfacial layer might increase the leakage current through the thin dielectric STO film.