Fabrication of Micro- and Nano-electrodes by Selective Chemical Vapor Deposition of Cu on Si Substrates Patterned with AZ5214{trade mark, serif} and PMMA

Abstract

Planar Cu electrodes with high length (starting from 1 mm down to 50 μm) and fine widths dimensions (starting from 20 μm and going down to 100 nm) were fabricated using selective chemical vapour deposition (SCVD) of the metal. For the fabrication, oxidized Si substrates were used on which a TiN layer was deposited and patterned either with AZ5214TM, for width dimensions of the order of microns, or by PMMA for lower dimensions. Then, Cu was deposited by SCVD on the exposed regions of the substrate only. Finally, the remaining polymers and the TiN were removed in acetone and by plasma etching, respectively. Due to the advanced CVD equipment used the above fabrication method proved to be robust, reproducible and with a high yield. The use of such equipment also assures a quite wide process window and inhibits the intrusion of other parameters which are known to destroy Cu SCVD.