Investigation of top electrode for PZT thick films based MEMS sensors

Christian Carstensen Hindrichsen, Thomas Pedersen, Paw T. Kristiansen, Rasmus Lou-Moller, Karsten Hansen, Erik Vilain Thomsen

    Research output: Contribution to journalJournal articleResearchpeer-review

    Abstract

    In this work processing of screen printed piezoelectric PZT thick films on silicon substrates is investigated for use in future MEMS devices. E-beam evaporated Al and Pt are patterned on PZT as a top electrode using a lift-off process with a line width down to 3 mu m. Three test structures are used to investigate the optimal thickness of the top electrode, the degradation of the piezoelectric properties of the PZT film in absence of a diffusion barrier layer and finally how to fabricate electrical interconnects down the edge of the PZT thick film. The roughness of the PZT is found to have a strong influence on the conductance of the top electrode influencing the optimal top electrode thickness. A 100 nm thick top electrode on the PZT thick film with a surface roughness of 273 nm has a 4.5 times higher resistance compared to a similar wire on a planar SiO2 surface which has a surface roughness of less than 10 nm. It is found that the piezoelectric properties of the PZT thick film are degraded up to 1,000 mu m away from a region of the PZT thick film that is exposed directly to the silicon substrate without a diffusion barrier layer. Finally, ferroelectric hysteresis loops are used to verify that the piezoelectric properties of the PZT thick film are unchanged after the processing of the top electrode.
    Original languageEnglish
    JournalJournal of Electroceramics
    Volume25
    Issue number2-4
    Pages (from-to)150-158
    ISSN1385-3449
    DOIs
    Publication statusPublished - 2010

    Keywords

    • Thick film
    • MEMS device
    • Top electrode
    • Piezoelectric
    • PZT

    Cite this

    Hindrichsen, Christian Carstensen ; Pedersen, Thomas ; Kristiansen, Paw T. ; Lou-Moller, Rasmus ; Hansen, Karsten ; Thomsen, Erik Vilain. / Investigation of top electrode for PZT thick films based MEMS sensors. In: Journal of Electroceramics. 2010 ; Vol. 25, No. 2-4. pp. 150-158.
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    title = "Investigation of top electrode for PZT thick films based MEMS sensors",
    abstract = "In this work processing of screen printed piezoelectric PZT thick films on silicon substrates is investigated for use in future MEMS devices. E-beam evaporated Al and Pt are patterned on PZT as a top electrode using a lift-off process with a line width down to 3 mu m. Three test structures are used to investigate the optimal thickness of the top electrode, the degradation of the piezoelectric properties of the PZT film in absence of a diffusion barrier layer and finally how to fabricate electrical interconnects down the edge of the PZT thick film. The roughness of the PZT is found to have a strong influence on the conductance of the top electrode influencing the optimal top electrode thickness. A 100 nm thick top electrode on the PZT thick film with a surface roughness of 273 nm has a 4.5 times higher resistance compared to a similar wire on a planar SiO2 surface which has a surface roughness of less than 10 nm. It is found that the piezoelectric properties of the PZT thick film are degraded up to 1,000 mu m away from a region of the PZT thick film that is exposed directly to the silicon substrate without a diffusion barrier layer. Finally, ferroelectric hysteresis loops are used to verify that the piezoelectric properties of the PZT thick film are unchanged after the processing of the top electrode.",
    keywords = "Thick film, MEMS device, Top electrode, Piezoelectric, PZT",
    author = "Hindrichsen, {Christian Carstensen} and Thomas Pedersen and Kristiansen, {Paw T.} and Rasmus Lou-Moller and Karsten Hansen and Thomsen, {Erik Vilain}",
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    Investigation of top electrode for PZT thick films based MEMS sensors. / Hindrichsen, Christian Carstensen; Pedersen, Thomas; Kristiansen, Paw T.; Lou-Moller, Rasmus; Hansen, Karsten; Thomsen, Erik Vilain.

    In: Journal of Electroceramics, Vol. 25, No. 2-4, 2010, p. 150-158.

    Research output: Contribution to journalJournal articleResearchpeer-review

    TY - JOUR

    T1 - Investigation of top electrode for PZT thick films based MEMS sensors

    AU - Hindrichsen, Christian Carstensen

    AU - Pedersen, Thomas

    AU - Kristiansen, Paw T.

    AU - Lou-Moller, Rasmus

    AU - Hansen, Karsten

    AU - Thomsen, Erik Vilain

    PY - 2010

    Y1 - 2010

    N2 - In this work processing of screen printed piezoelectric PZT thick films on silicon substrates is investigated for use in future MEMS devices. E-beam evaporated Al and Pt are patterned on PZT as a top electrode using a lift-off process with a line width down to 3 mu m. Three test structures are used to investigate the optimal thickness of the top electrode, the degradation of the piezoelectric properties of the PZT film in absence of a diffusion barrier layer and finally how to fabricate electrical interconnects down the edge of the PZT thick film. The roughness of the PZT is found to have a strong influence on the conductance of the top electrode influencing the optimal top electrode thickness. A 100 nm thick top electrode on the PZT thick film with a surface roughness of 273 nm has a 4.5 times higher resistance compared to a similar wire on a planar SiO2 surface which has a surface roughness of less than 10 nm. It is found that the piezoelectric properties of the PZT thick film are degraded up to 1,000 mu m away from a region of the PZT thick film that is exposed directly to the silicon substrate without a diffusion barrier layer. Finally, ferroelectric hysteresis loops are used to verify that the piezoelectric properties of the PZT thick film are unchanged after the processing of the top electrode.

    AB - In this work processing of screen printed piezoelectric PZT thick films on silicon substrates is investigated for use in future MEMS devices. E-beam evaporated Al and Pt are patterned on PZT as a top electrode using a lift-off process with a line width down to 3 mu m. Three test structures are used to investigate the optimal thickness of the top electrode, the degradation of the piezoelectric properties of the PZT film in absence of a diffusion barrier layer and finally how to fabricate electrical interconnects down the edge of the PZT thick film. The roughness of the PZT is found to have a strong influence on the conductance of the top electrode influencing the optimal top electrode thickness. A 100 nm thick top electrode on the PZT thick film with a surface roughness of 273 nm has a 4.5 times higher resistance compared to a similar wire on a planar SiO2 surface which has a surface roughness of less than 10 nm. It is found that the piezoelectric properties of the PZT thick film are degraded up to 1,000 mu m away from a region of the PZT thick film that is exposed directly to the silicon substrate without a diffusion barrier layer. Finally, ferroelectric hysteresis loops are used to verify that the piezoelectric properties of the PZT thick film are unchanged after the processing of the top electrode.

    KW - Thick film

    KW - MEMS device

    KW - Top electrode

    KW - Piezoelectric

    KW - PZT

    U2 - 10.1007/s10832-010-9606-7

    DO - 10.1007/s10832-010-9606-7

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    SN - 1385-3449

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    ER -