Freestanding ultra-thin silica

Rui Zhao, Hongyeun Kim, Joshua Stapleton, Zi Kui Liu, Joshua Robinson

Research output: Contribution to journalArticlepeer-review

1 Scopus citations


Silica (SiOx) thin films are promising for a wide range of applications, including catalysis, separation technology, biomedicine, or transparent super-hydrophilic films. Here, we present a study demonstrating a unique way of producing ultra-thin, freestanding silica films via silicon etching. This method utilizes silicon wafers with thermally oxidized surfaces and two common inorganic elements (sulfur and tellurium), which leads to high-rate chemical etching of the Si substrate, leaving behind freestanding silica layers. Thermodynamic calculations of the tellurium-silicon-sulfur (Te-Si-S) ternary phase diagram suggest that the removal of the Si substrate from the silica layers is due to chemical reactions that result in liquid/vapor formation of Si-S and Si-Te phases. Importantly, the chemical and physical properties of the silica film post-etch are comparable to those of the starting material. The process described here provides a route to produce large area, flexible glass substrates with widely tunable thicknesses from tens to thousands of nanometers.

Original languageEnglish (US)
Article number025126
JournalAIP Advances
Issue number2
StatePublished - Feb 1 2020

All Science Journal Classification (ASJC) codes

  • Physics and Astronomy(all)


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