Superplastic behavior of silica nanowires obtained by direct patterning of silsesquioxane-based precursors

Mustafa Yilmaz, Nicole Wollschläger, Mohammad Nasr Esfahani, Werner Osterle, Yusuf Leblebici, B. Erdem Alaca*

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review


Silica nanowires spanning 10 μm-deep trenches are fabricated from different types of silsesquioxane-based precursors by direct e-beam patterning on silicon followed by release through deep reactive ion etching. Nanowire aspect ratios as large as 150 are achieved with a critical dimension of about 50 nm and nearly rectangular cross-sections. In situ bending tests are carried out inside a scanning electron microscope, where the etch depth of 10 provides sufficient space for deformation. Silica NWs are indeed observed to exhibit superplastic behavior without fracture with deflections reaching the full etch depth, about two orders of magnitude larger than the nanowire thickness. A large-deformation elastic bending model is utilized for predicting the deviation from the elastic behavior. The results of forty different tests indicate a critical stress level of 0.1-0.4 GPa for the onset of plasticity. The study hints at the possibility of fabricating silica nanowires in a monolithic fashion through direct e-beam patterning of silsesquioxane-based resins. The fabrication technology is compatible with semiconductor manufacturing and provides silica nanowires with a very good structural integrity.

Original languageEnglish
Article number115302
Number of pages10
Issue number11
Publication statusPublished - 15 Feb 2017

Bibliographical note

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© 2017 IOP Publishing Ltd.


  • HSQ
  • in situ bending tests
  • silica nanowires
  • superplasticity

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