Controlling the crystallinity and roughness of atomic layer deposited titanium dioxide films

Riikka Puurunen, Timo Sajavaara, Eero Santala, Ville Miikkulainen, Tapio Saukkonen, Mikko Laitinen, Markku Leskelä

Research output: Contribution to journalArticleScientificpeer-review

33 Citations (Scopus)

Abstract

The surface roughness of thin films is an important parameter related to the sticking behaviour of surfaces in the manufacturing of microelectomechanical systems (MEMS). In this work, TiO2 films made by atomic layer deposition (ALD) with the TiCl4–H2O process were characterized for their growth, roughness and crystallinity as function of deposition temperature (110–300 °C), film thickness (up to ∼100 nm) and substrate (thermal SiO2, RCA-cleaned Si, Al2O3). TiO2 films got rougher with increasing film thickness and to some extent with increasing deposition temperature. The substrate drastically influenced the crystallization behaviour of the film: for films of about 20 nm thickness, on thermal SiO2 and RCA-cleaned Si, anatase TiO2 crystal diameter was about 40 nm, while on Al2O3 surface the diameter was about a micrometer. The roughness could be controlled from 0.2 nm up to several nanometers, which makes the TiO2 films candidates for adhesion engineering in MEMS.
Original languageEnglish
Pages (from-to)8101-8107
JournalJournal of Nanoscience and Nanotechnology
Volume11
Issue number9
DOIs
Publication statusPublished - 2011
MoE publication typeA1 Journal article-refereed

Keywords

  • Atomic layer deposition
  • TiO(2)
  • roughness
  • anatase

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    Puurunen, R., Sajavaara, T., Santala, E., Miikkulainen, V., Saukkonen, T., Laitinen, M., & Leskelä, M. (2011). Controlling the crystallinity and roughness of atomic layer deposited titanium dioxide films. Journal of Nanoscience and Nanotechnology, 11(9), 8101-8107. https://doi.org/10.1166/jnn.2011.5060