HF etching of sacrificial spin-on glass in straight and junctioned microchannels for MEMS microstructure release

Sacrificial spin-on glass (SOG) etching in straight and junctioned microchannels using hydrofluoric acid (HF) was investigated. SOG etch rates in both reaction-dominant and diffusion-dominant regimes for various HF concentrations were studied. An etching model based on a non-first-order chemical rea...

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Main Authors: Hamzah, A.A., Majlis, B.Y., Ahmad, I.
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Published: 2017
Online Access:http://dspace.uniten.edu.my:8080/jspui/handle/123456789/5296
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spelling my.uniten.dspace-52962017-11-15T02:57:22Z HF etching of sacrificial spin-on glass in straight and junctioned microchannels for MEMS microstructure release Hamzah, A.A. Majlis, B.Y. Ahmad, I. Sacrificial spin-on glass (SOG) etching in straight and junctioned microchannels using hydrofluoric acid (HF) was investigated. SOG etch rates in both reaction-dominant and diffusion-dominant regimes for various HF concentrations were studied. An etching model based on a non-first-order chemical reaction/steady-state diffusion etching mechanism is presented to compensate for the etching effect at the channel junction. Straight microchannels 1500 μm in length and various widths were fabricated on silicon substrate by coating a hardened photoresist layer over rectangular-shaped SOG layers. Junctioned microchannels were fabricated on silicon by filling SOG into deep reactive ion etching (DRIE)-etched microchannels. The samples were time-etched in HF solution and etch-front propagation was observed under an optical microscope. It is observed that the SOG etch rate is linear in the reaction-limited region and drops approximately 70% in the diffusion-limited region. The SOG etch rate in microchannels is independent of channel width and depth. The SOG etch rate at the T-junction is 0.67 times lower than its etch rate in straight channels due to the instantaneous drop in HF concentration. This behavior is well embodied by the presented numerical model. Finally, 5% HF is suitable for release etch due to its acceptable etch rate while being less damaging to microelectromechanical system (MEMS) microstructures. © 2007 The Electrochemical Society. 2017-11-15T02:57:22Z 2017-11-15T02:57:22Z 2007 http://dspace.uniten.edu.my:8080/jspui/handle/123456789/5296
institution Universiti Tenaga Nasional
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country Malaysia
content_provider Universiti Tenaga Nasional
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description Sacrificial spin-on glass (SOG) etching in straight and junctioned microchannels using hydrofluoric acid (HF) was investigated. SOG etch rates in both reaction-dominant and diffusion-dominant regimes for various HF concentrations were studied. An etching model based on a non-first-order chemical reaction/steady-state diffusion etching mechanism is presented to compensate for the etching effect at the channel junction. Straight microchannels 1500 μm in length and various widths were fabricated on silicon substrate by coating a hardened photoresist layer over rectangular-shaped SOG layers. Junctioned microchannels were fabricated on silicon by filling SOG into deep reactive ion etching (DRIE)-etched microchannels. The samples were time-etched in HF solution and etch-front propagation was observed under an optical microscope. It is observed that the SOG etch rate is linear in the reaction-limited region and drops approximately 70% in the diffusion-limited region. The SOG etch rate in microchannels is independent of channel width and depth. The SOG etch rate at the T-junction is 0.67 times lower than its etch rate in straight channels due to the instantaneous drop in HF concentration. This behavior is well embodied by the presented numerical model. Finally, 5% HF is suitable for release etch due to its acceptable etch rate while being less damaging to microelectromechanical system (MEMS) microstructures. © 2007 The Electrochemical Society.
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author Hamzah, A.A.
Majlis, B.Y.
Ahmad, I.
spellingShingle Hamzah, A.A.
Majlis, B.Y.
Ahmad, I.
HF etching of sacrificial spin-on glass in straight and junctioned microchannels for MEMS microstructure release
author_facet Hamzah, A.A.
Majlis, B.Y.
Ahmad, I.
author_sort Hamzah, A.A.
title HF etching of sacrificial spin-on glass in straight and junctioned microchannels for MEMS microstructure release
title_short HF etching of sacrificial spin-on glass in straight and junctioned microchannels for MEMS microstructure release
title_full HF etching of sacrificial spin-on glass in straight and junctioned microchannels for MEMS microstructure release
title_fullStr HF etching of sacrificial spin-on glass in straight and junctioned microchannels for MEMS microstructure release
title_full_unstemmed HF etching of sacrificial spin-on glass in straight and junctioned microchannels for MEMS microstructure release
title_sort hf etching of sacrificial spin-on glass in straight and junctioned microchannels for mems microstructure release
publishDate 2017
url http://dspace.uniten.edu.my:8080/jspui/handle/123456789/5296
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score 13.211869