CVD of Alumina on Carbon and Silicon Carbide Microfiber Substrates for Microelectrode Development

✍ Scribed by D. M. Giolando; J. R. Kirchhoff; H. Mueller; P. Q. Nguyen; I. N. Odeh

• Publisher: John Wiley and Sons
• Year: 2002
• Tongue: English
• Weight: 289 KB
• Volume: 8
• Category: Article
• ISSN: 0948-1907
• DOI: 10.1002/1521-3862(20020503)8:3<93::aid-cvde93>3.0.co;2-b

✦ Synopsis

Using a vacuum CVD technique, alumina films were deposited on 10 lm diameter carbon fibers, and 120 lm diameter silicon carbide fibers. This was accomplished by exposing resistively heated microfiber substrates to a sublimate of [Al(O-t Bu) 3 ] 2 , while the reaction chamber was maintained at 120 C under a pressure of 0.15 torr. The coated substrates were then sealed into glass capillaries, using an epoxy sealant, to form microelectrode devices. The quality of the alumina films was found to be dependent on the substrate temperature, with optimum film quality being obtained at substrate temperatures between 750 C and 800 C. Film thickness was controlled by deposition time, and films from 1±100 lm were routinely produced. Films were characterized by microscopy and electrochemical techniques.