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

9 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

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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",
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journal = "Sensors and Actuators A: Physical",
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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

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EP - 245

JO - Sensors and Actuators A: Physical

JF - Sensors and Actuators A: Physical

SN - 0924-4247

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