Reducing stiction in microelectromechanical systems by rough nanometer-scale films grown by atomic layer deposition

Riikka Puurunen (Corresponding Author), Ari Häärä, Heini Saloniemi, James Dekker, Markku Kainlauri, Harri Pohjonen, Tommi Suni, Jyrki Kiihamäki, E. Santala, M. Leskelä, Hannu Kattelus

    Research output: Contribution to journalArticleScientificpeer-review

    10 Citations (Scopus)

    Abstract

    Atomic layer deposition (ALD) can be used to grow pinhole-free nanometer-thin conformal inorganic films at low temperatures, making it of interest for many applications in MEMS (microelectromechanical systems). Stiction during device operation remains one of the mechanisms leading to permanent failure of operating silicon-based MEMS. This work investigated whether stiction in MEMS could be decreased by applying rough thin inorganic ALD films. Test structures based on the cantilever-beam-array (CBA) method were fabricated and coated with 2–50 nm thick ALD layers varying in chemical nature and roughness: Al2O3, TiO2, MoN and Ta(Al)N. Smooth ALD films (AFM rms roughness below or equal to ca. 0.5 nm) were not observed to decrease stiction markedly. Crystalline films with roughness in the nanometer range (AFM rms ca. 1–3 nm) decreased stiction, resulting in a decrease of adhesion energy by up to four orders of magnitude as compared to Si and other smooth films. On the basis of this work, rough crystalline nanoscale ALD films are candidates for anti-stiction layers in MEMS.
    Original languageEnglish
    Pages (from-to)240-245
    Number of pages6
    JournalSensors and Actuators A: Physical
    Volume188
    DOIs
    Publication statusPublished - 2012
    MoE publication typeA1 Journal article-refereed
    Event16th International Conference on Solid-State Sensors, Actuators and Microsystems, Transducers’11
    - Beijing, China
    Duration: 5 Jun 20119 Jun 2011

    Fingerprint

    stiction
    Stiction
    Atomic layer deposition
    atomic layer epitaxy
    microelectromechanical systems
    MEMS
    roughness
    Surface roughness
    atomic force microscopy
    Crystalline materials
    cantilever beams
    Cantilever beams
    Silicon
    pinholes
    adhesion
    Adhesion
    silicon

    Keywords

    • Al 2O 3
    • atomic layer deposition
    • cantilever beam array
    • MoN
    • stiction
    • TiO 2

    Cite this

    Puurunen, Riikka ; Häärä, Ari ; Saloniemi, Heini ; Dekker, James ; Kainlauri, Markku ; Pohjonen, Harri ; Suni, Tommi ; Kiihamäki, Jyrki ; Santala, E. ; Leskelä, M. ; Kattelus, Hannu. / Reducing stiction in microelectromechanical systems by rough nanometer-scale films grown by atomic layer deposition. In: Sensors and Actuators A: Physical. 2012 ; Vol. 188. pp. 240-245.
    @article{2a6f6a8f1f0e49bab48f705012906873,
    title = "Reducing stiction in microelectromechanical systems by rough nanometer-scale films grown by atomic layer deposition",
    abstract = "Atomic layer deposition (ALD) can be used to grow pinhole-free nanometer-thin conformal inorganic films at low temperatures, making it of interest for many applications in MEMS (microelectromechanical systems). Stiction during device operation remains one of the mechanisms leading to permanent failure of operating silicon-based MEMS. This work investigated whether stiction in MEMS could be decreased by applying rough thin inorganic ALD films. Test structures based on the cantilever-beam-array (CBA) method were fabricated and coated with 2–50 nm thick ALD layers varying in chemical nature and roughness: Al2O3, TiO2, MoN and Ta(Al)N. Smooth ALD films (AFM rms roughness below or equal to ca. 0.5 nm) were not observed to decrease stiction markedly. Crystalline films with roughness in the nanometer range (AFM rms ca. 1–3 nm) decreased stiction, resulting in a decrease of adhesion energy by up to four orders of magnitude as compared to Si and other smooth films. On the basis of this work, rough crystalline nanoscale ALD films are candidates for anti-stiction layers in MEMS.",
    keywords = "Al 2O 3, atomic layer deposition, cantilever beam array, MoN, stiction, TiO 2",
    author = "Riikka Puurunen and Ari H{\"a}{\"a}r{\"a} and Heini Saloniemi and James Dekker and Markku Kainlauri and Harri Pohjonen and Tommi Suni and Jyrki Kiiham{\"a}ki and E. Santala and M. Leskel{\"a} and Hannu Kattelus",
    note = "Project code: 73742",
    year = "2012",
    doi = "10.1016/j.sna.2012.01.040",
    language = "English",
    volume = "188",
    pages = "240--245",
    journal = "Sensors and Actuators A: Physical",
    issn = "0924-4247",
    publisher = "Elsevier",

    }

    Reducing stiction in microelectromechanical systems by rough nanometer-scale films grown by atomic layer deposition. / Puurunen, Riikka (Corresponding Author); Häärä, Ari; Saloniemi, Heini; Dekker, James; Kainlauri, Markku; Pohjonen, Harri; Suni, Tommi; Kiihamäki, Jyrki; Santala, E.; Leskelä, M.; Kattelus, Hannu.

    In: Sensors and Actuators A: Physical, Vol. 188, 2012, p. 240-245.

    Research output: Contribution to journalArticleScientificpeer-review

    TY - JOUR

    T1 - Reducing stiction in microelectromechanical systems by rough nanometer-scale films grown by atomic layer deposition

    AU - Puurunen, Riikka

    AU - Häärä, Ari

    AU - Saloniemi, Heini

    AU - Dekker, James

    AU - Kainlauri, Markku

    AU - Pohjonen, Harri

    AU - Suni, Tommi

    AU - Kiihamäki, Jyrki

    AU - Santala, E.

    AU - Leskelä, M.

    AU - Kattelus, Hannu

    N1 - Project code: 73742

    PY - 2012

    Y1 - 2012

    N2 - Atomic layer deposition (ALD) can be used to grow pinhole-free nanometer-thin conformal inorganic films at low temperatures, making it of interest for many applications in MEMS (microelectromechanical systems). Stiction during device operation remains one of the mechanisms leading to permanent failure of operating silicon-based MEMS. This work investigated whether stiction in MEMS could be decreased by applying rough thin inorganic ALD films. Test structures based on the cantilever-beam-array (CBA) method were fabricated and coated with 2–50 nm thick ALD layers varying in chemical nature and roughness: Al2O3, TiO2, MoN and Ta(Al)N. Smooth ALD films (AFM rms roughness below or equal to ca. 0.5 nm) were not observed to decrease stiction markedly. Crystalline films with roughness in the nanometer range (AFM rms ca. 1–3 nm) decreased stiction, resulting in a decrease of adhesion energy by up to four orders of magnitude as compared to Si and other smooth films. On the basis of this work, rough crystalline nanoscale ALD films are candidates for anti-stiction layers in MEMS.

    AB - Atomic layer deposition (ALD) can be used to grow pinhole-free nanometer-thin conformal inorganic films at low temperatures, making it of interest for many applications in MEMS (microelectromechanical systems). Stiction during device operation remains one of the mechanisms leading to permanent failure of operating silicon-based MEMS. This work investigated whether stiction in MEMS could be decreased by applying rough thin inorganic ALD films. Test structures based on the cantilever-beam-array (CBA) method were fabricated and coated with 2–50 nm thick ALD layers varying in chemical nature and roughness: Al2O3, TiO2, MoN and Ta(Al)N. Smooth ALD films (AFM rms roughness below or equal to ca. 0.5 nm) were not observed to decrease stiction markedly. Crystalline films with roughness in the nanometer range (AFM rms ca. 1–3 nm) decreased stiction, resulting in a decrease of adhesion energy by up to four orders of magnitude as compared to Si and other smooth films. On the basis of this work, rough crystalline nanoscale ALD films are candidates for anti-stiction layers in MEMS.

    KW - Al 2O 3

    KW - atomic layer deposition

    KW - cantilever beam array

    KW - MoN

    KW - stiction

    KW - TiO 2

    U2 - 10.1016/j.sna.2012.01.040

    DO - 10.1016/j.sna.2012.01.040

    M3 - Article

    VL - 188

    SP - 240

    EP - 245

    JO - Sensors and Actuators A: Physical

    JF - Sensors and Actuators A: Physical

    SN - 0924-4247

    ER -