Fabrication of precise copper micro-coils using electrolytic etching

• Published in: Microelectronic engineering Vol. 97; pp. 212 - 215
• Main Authors: Horiuchi, Toshiyuki, Ishii, Hidetoshi
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier B.V 01-09-2012; Elsevier
• Subjects: Applied sciences; Cross-disciplinary physics: materials science; rheology; Dissociation etching; Electrolytic etching; Electronics; Exact sciences and technology; Helical pattern; Laser lithography; Materials science; Methods of nanofabrication; Micro-coil; Microelectronic fabrication (materials and surfaces technology); Nanolithography; Physics; Semiconductor electronics. Microelectronics. Optoelectronics. Solid state devices; Laser lithography; Helical pattern; Dissociation etching; Electrolytic etching; Micro-coil; Heat treatment; Lithography; Power supply circuits; Etching rate; Chemical etching; Sodium chloride; Switching; Coil; Ammonium chloride; Thickness; Microelectronic fabrication; Engraving; Homogeneity; Resist; Aqueous solution; Copper; Room temperature; On off effect
• ISSN: 0167-9317; 1873-5568
• DOI: 10.1016/j.mee.2012.03.019

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► Helical patterning on copper pipes. ► Electrolytic etching. ► Precise micro-coils.
Precise and homogeneous copper micro-coils were fabricated using electrolytic etching in aqueous solution of sodium chloride and ammonium chloride. It was clarified that the etching rate was hardly influenced by the resist pattern thickness and the etching voltage, but only depended on the helical space pattern width. Start and stop of the etching was exactly controlled by switching on and off the power supply circuit, and the etching was practiced under the room temperature without heating the specimens. The sidewall surfaces of the etched coils were very much smoother than those of the coils fabricated by the conventional chemical etching, and very favorable coil width homogeneity was obtained even for narrow space patterns with a width around 10μm.