Characterization of deep wet etching of fused silica glass for single cell and optical sensor deposition

Haixin Zhu, Mark Holl, Tathagata Ray, Shivani Bhushan, Deirdre Meldrum

Research output: Contribution to journalArticle

49 Citations (Scopus)

Abstract

The development of a high-throughput single-cell metabolic rate monitoring system relies on the use of transparent substrate material for a single cell-trapping platform. The high optical transparency, high chemical resistance, improved surface quality and compatibility with the silicon micromachining process of fused silica make it very attractive and desirable for this application. In this paper, we report the results from the development and characterization of a hydrofluoric acid (HF) based deep wet-etch process on fused silica. The pin holes and notching defects of various single-coated masking layers during the etching are characterized and the most suitable masking materials are identified for different etch depths. The dependence of the average etch rate and surface roughness on the etch depth, impurity concentration and HF composition are also examined. The resulting undercut from the deep HF etch using various masking materials is also investigated. The developed and characterized process techniques have been successfully implemented in the fabrication of micro-well arrays for single cell trapping and sensor deposition. Up to 60 νm deep micro-wells have been etched in a fused silica substrate with over 90% process yield and repeatability. To our knowledge, such etch depth has never been achieved in a fused silica substrate by using a non-diluted HF etchant and a single-coated masking layer at room temperature.

Original languageEnglish (US)
Article number065013
JournalJournal of Micromechanics and Microengineering
Volume19
Issue number6
DOIs
StatePublished - 2009

Fingerprint

Hydrofluoric Acid
Hydrofluoric acid
Wet etching
Optical sensors
Fused silica
Substrates
Chemical resistance
Micromachining
Silicon
Transparency
Surface properties
Etching
Surface roughness
Throughput
Impurities
Fabrication
Defects
Monitoring
Sensors
Chemical analysis

ASJC Scopus subject areas

  • Mechanical Engineering
  • Electrical and Electronic Engineering
  • Mechanics of Materials
  • Electronic, Optical and Magnetic Materials

Cite this

Characterization of deep wet etching of fused silica glass for single cell and optical sensor deposition. / Zhu, Haixin; Holl, Mark; Ray, Tathagata; Bhushan, Shivani; Meldrum, Deirdre.

In: Journal of Micromechanics and Microengineering, Vol. 19, No. 6, 065013, 2009.

Research output: Contribution to journalArticle

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