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Vapor Phase Metal-Assisted Chemical Etching of Silicon



Owen J. Hildreth, Daniel R. Schmidt


This work introduces and explores vapor phase metal‐assisted chemical etching (VP‐MaCE) of silicon as a method to bypass some of the challenges found in traditional liquid phase metal‐assisted chemical etching (LP‐MaCE). Average etch rates for Ag, Au, and Pd/Au catalysts are established at 31, 70, and 96 nm/min respectively, and the relationship between etch rate and substrate temperature is examined experimentally. Just as with LP‐MaCE, 3D catalyst motion is maintained and three‐dimensional structures are fabricated with nanoparticle‐ and lithography‐patterned catalysts. VP‐MaCE produces less microporous silicon compared with LP‐MaCE and the diffusion/reduction distance of Ag+ ions is significantly reduced. This process sacrifices etch rate for increased etch uniformity and lower stiction for applications in micro‐electromechanical systems (MEMS) processing.
Advanced Functional Materials


vapor phase metal-assisted chemical etching, VP-MaCE, silicon, traditional liquid phase metal-assisted chemical etching, LP-MaCE, 3D catalyst motion, nanoparticle catalysts, lithography-patterned catalysts, vapor phase, electroless


Hildreth, O. and Schmidt, D. (2014), Vapor Phase Metal-Assisted Chemical Etching of Silicon, Advanced Functional Materials, [online], (Accessed June 14, 2024)


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Created June 24, 2014, Updated November 9, 2020