Fabrication of ultramicroelectrodes based on PECVD

Ultramicroelectrode (UME) is one of the key devices of electrochemical instrument. The method of the UMEs fabrication based on plasma enhanced chemical vapor deposition (PECVD) technology is described. PECVD technology is applied to produce the insulating films of UMEs that are proved to have uniform geometries, controllable thickness of insulating films and good adherences at the interfaces. Three types of UMEs were constructed based on PECVD technology. The Au disk UMEs were fabricated by depositing silicon nitride thin films onto the surfaces of 25μm diameter Au fibers. The Au ring UMEs were constructed by sputtering Au films onto the surfaces of optical fibers and then depositing silicon nitride thin films onto the surfaces of Au films. Multilayered materials and conventional microfabrication techniques were applied to produce the band UME arrays and PECVD technology was used to produce the insulating films.