Electrical properties of Tantalum based composite oxide films

Hannu Kattelus, Markku Ylilammi, Jorma Salmi, Timo Ranta-Aho, Erja Nykänen, Ilkka Suni

    Research output: Chapter in Book/Report/Conference proceedingConference article in proceedingsScientificpeer-review

    25 Citations (Scopus)


    Tantalum oxide is a widely used insulator in electronic applications requiring high permittivity. When deposited at low temperature, tantalum oxide films, however, often exhibit large leakage current. A common way to reduce leakage is to anneal the films in an ambient containing extremely reactive oxygen species, or at high temperature in dry oxygen. A different approach is to use composite oxide materials. We have studied layered tantalum based oxide films deposited by Atomic Layer Epitaxy, and observed that the leakage current is decreased by several orders of magnitude when a fraction of tantalum oxide is replaced by another oxide, such as aluminum or hafnium oxide. Leakage current density of 40 nA/cm² in the electric field of 1 MV/cm is attained for unannealed Ta-Hf-O film deposited at 300°C. Layered composite insulators are an interesting new class of materials, and ALE proves to be a useful method for depositing them.
    Original languageEnglish
    Title of host publicationAmorphous Insulating Thin Films
    Subtitle of host publicationSymposium G
    EditorsRoderick A.B. Devine, Jerzy Kanicki, Masakiyo Matsumura, William L. Warren
    Place of PublicationPittsburgh
    PublisherMaterials Research Society
    ISBN (Print)978-1-55899-179-8
    Publication statusPublished - 1993
    MoE publication typeA4 Article in a conference publication
    EventMaterials Research Society Fall Meeting 1992 - Boston, United States
    Duration: 30 Nov 19924 Dec 1992

    Publication series

    SeriesMaterials Research Society Symposia Proceedings


    ConferenceMaterials Research Society Fall Meeting 1992
    Country/TerritoryUnited States


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