Dependency of dishing on polish time and slurry chemistry in Cu CMP

V. Nguyen Hoang, H. van Kranenburg, P.H. Woerlee

    Research output: Contribution to journalArticleAcademicpeer-review

    68 Citations (Scopus)

    Abstract

    In this paper the influences of slurry chemistry and thickness of the copper layer on dishing will be discussed. The dishing is studied for different patterns and variable polishing times. We found that the concentration of the oxidiser and the thickness of copper layer have a strong impact on dishing. The larger Cu features develop dishing at a higher rate than smaller structures during overpolishing. The experimental results lead to the following hypothesis for the Cu removal and surface passivation. The oxidizer (H2O2) reacts with Cu in an acidic slurry (pH 4) and Cu2+ ions are formed. The anions of the carboxylic acid react with Cu2+ ions and form an insoluble salt (R(COO)2Cu) which passivates the surface. This passivation layer is removed in protruding areas by mechanical abrasion. Once removed from the surface, the ‘metallic soap’ particles are swept away by the turbulent motion in the slurry.
    Original languageUndefined
    Pages (from-to)403-410
    JournalMicroelectronic engineering
    Volume50
    Issue number1-4
    DOIs
    Publication statusPublished - 2000

    Keywords

    • METIS-111621
    • Copper
    • Dishing
    • IR-74306
    • Chemical mechanical polishing

    Cite this

    Nguyen Hoang, V. ; van Kranenburg, H. ; Woerlee, P.H. / Dependency of dishing on polish time and slurry chemistry in Cu CMP. In: Microelectronic engineering. 2000 ; Vol. 50, No. 1-4. pp. 403-410.
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    abstract = "In this paper the influences of slurry chemistry and thickness of the copper layer on dishing will be discussed. The dishing is studied for different patterns and variable polishing times. We found that the concentration of the oxidiser and the thickness of copper layer have a strong impact on dishing. The larger Cu features develop dishing at a higher rate than smaller structures during overpolishing. The experimental results lead to the following hypothesis for the Cu removal and surface passivation. The oxidizer (H2O2) reacts with Cu in an acidic slurry (pH 4) and Cu2+ ions are formed. The anions of the carboxylic acid react with Cu2+ ions and form an insoluble salt (R(COO)2Cu) which passivates the surface. This passivation layer is removed in protruding areas by mechanical abrasion. Once removed from the surface, the ‘metallic soap’ particles are swept away by the turbulent motion in the slurry.",
    keywords = "METIS-111621, Copper, Dishing, IR-74306, Chemical mechanical polishing",
    author = "{Nguyen Hoang}, V. and {van Kranenburg}, H. and P.H. Woerlee",
    year = "2000",
    doi = "10.1016/S0167-9317(99)00308-1",
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    Dependency of dishing on polish time and slurry chemistry in Cu CMP. / Nguyen Hoang, V.; van Kranenburg, H.; Woerlee, P.H.

    In: Microelectronic engineering, Vol. 50, No. 1-4, 2000, p. 403-410.

    Research output: Contribution to journalArticleAcademicpeer-review

    TY - JOUR

    T1 - Dependency of dishing on polish time and slurry chemistry in Cu CMP

    AU - Nguyen Hoang, V.

    AU - van Kranenburg, H.

    AU - Woerlee, P.H.

    PY - 2000

    Y1 - 2000

    N2 - In this paper the influences of slurry chemistry and thickness of the copper layer on dishing will be discussed. The dishing is studied for different patterns and variable polishing times. We found that the concentration of the oxidiser and the thickness of copper layer have a strong impact on dishing. The larger Cu features develop dishing at a higher rate than smaller structures during overpolishing. The experimental results lead to the following hypothesis for the Cu removal and surface passivation. The oxidizer (H2O2) reacts with Cu in an acidic slurry (pH 4) and Cu2+ ions are formed. The anions of the carboxylic acid react with Cu2+ ions and form an insoluble salt (R(COO)2Cu) which passivates the surface. This passivation layer is removed in protruding areas by mechanical abrasion. Once removed from the surface, the ‘metallic soap’ particles are swept away by the turbulent motion in the slurry.

    AB - In this paper the influences of slurry chemistry and thickness of the copper layer on dishing will be discussed. The dishing is studied for different patterns and variable polishing times. We found that the concentration of the oxidiser and the thickness of copper layer have a strong impact on dishing. The larger Cu features develop dishing at a higher rate than smaller structures during overpolishing. The experimental results lead to the following hypothesis for the Cu removal and surface passivation. The oxidizer (H2O2) reacts with Cu in an acidic slurry (pH 4) and Cu2+ ions are formed. The anions of the carboxylic acid react with Cu2+ ions and form an insoluble salt (R(COO)2Cu) which passivates the surface. This passivation layer is removed in protruding areas by mechanical abrasion. Once removed from the surface, the ‘metallic soap’ particles are swept away by the turbulent motion in the slurry.

    KW - METIS-111621

    KW - Copper

    KW - Dishing

    KW - IR-74306

    KW - Chemical mechanical polishing

    U2 - 10.1016/S0167-9317(99)00308-1

    DO - 10.1016/S0167-9317(99)00308-1

    M3 - Article

    VL - 50

    SP - 403

    EP - 410

    JO - Microelectronic engineering

    JF - Microelectronic engineering

    SN - 0167-9317

    IS - 1-4

    ER -