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Electrochemical Micromachining as an Enabling Technology for Advanced Silicon Microstructuring
Author(s) -
Bassu Margherita,
Surdo Salvatore,
Strambini Lucanos Marsilio,
Barillaro Giuseppe
Publication year - 2012
Publication title -
advanced functional materials
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 6.069
H-Index - 322
eISSN - 1616-3028
pISSN - 1616-301X
DOI - 10.1002/adfm.201102124
Subject(s) - materials science , microsystem , silicon , surface micromachining , microelectronics , etching (microfabrication) , microfabrication , nanotechnology , micrometer , reactive ion etching , dry etching , isotropic etching , bulk micromachining , fabrication , optoelectronics , optics , medicine , alternative medicine , physics , pathology , layer (electronics)
Based on previous theoretical and experimental results on the electrochemical etching of silicon in HF‐based aqueous electrolytes, it is shown for the first time that silicon microstructures of various shapes and silicon microsystems of high complexity can be effectively fabricated in any research lab with sub‐micrometer accuracy and high aspect ratio values (about 100). This is well beyond any up‐to‐date wet or dry microstructuring approach and is achieved using a wet etching, low‐cost technology: silicon electrochemical micromachining (ECM). Dynamic control of the etching anisotropy (from 1 to 0) as the electrochemical etching progresses allows the silicon dissolution to be switched in real‐time from the anisotropic to the isotropic regime and enables advanced silicon microstructuring to be achieved through the use of high‐aspect‐ratio functional and sacrificial structures, the former being functional to the microsystem operation and the latter being sacrificed for accurate microsystem fabrication. World‐wide dissemination of the ECM technology for silicon microstructuring is envisaged in the near future, due to its low cost and high flexibility, with high‐potential impact on, though not limited to, the broad field of microelectronics and microfabrication.