Material and electrical characterizations of high-k Ta2O5 dielectric material deposited on polycrystalline silicon and single crystalline substrate

•RTA annealing can mitigate bulk defects in Ta2O5 by repairing oxygen vacancies.•Multiple electrical and material analyses on two types of substrates.•The interface on top of a single crystalline substrate had fewer structural defects.•The dielectrics on a single crystalline substrate possessed superior characteristics.

Samples of high-k Ta2O5 film as a high-k gate dielectric sputtered on both a single crystalline substrate and a polycrystalline silicon substrate and annealed at different temperatures were fabricated and compared. Samples were examined using various material and electrical analyses, including X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), atomic force spectroscopy (AFM), equivalent oxide thickness (EOT), JE characteristics, charge-to-breakdown Weibull plots, and gate voltage shift versus stress time. The research concludes that a Ta2O5 dielectric on a single crystalline substrate had fewer structural defects than a high-k/polysilicon interface, forming a dielectric with better material properties and electrical reliability.

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