Multi-walled carbon nanotube composites (Au⁺MWCNT) for electrical interconnection and reduction of microelectronic corrosion

Electro-migration and galvanic corrosion can be associated with subsystem degradation over time. In this investigation electro-migration (Ni²⁺, Cu²⁺, Pb²⁺/Sn²⁺) and galvanic corrosion was identified as occurring on plated subsystem microelectronic surfaces. An intensive surface study was undertaken to characterize and identify microelectronic contaminants, migrated ions and oxides. Multi-layer microelectronic test vehicles were prepared using electrolytic (10-20V DC, 2amp bias) ion deposition, and were surface characterized by SEM, EDS, Optical microscopy, and electrical THB testing to identify and quantify subsystem plating thickness, electro-migration, interstitial cracking, and galvanic corrosion sites. Test vehicle surface plating thickness was measured and ranged from 66-161 micro-inches. Bulk conductivity measurements revealed pre and post humidity exposure resistances of 0.5 - 0.8 ohms, and 1.6 - 0.8 ohms respectively. Two novel electrically conductive MWCNTs with Au⁺ metallic composition were identified as a potential higher conductivity electrical interconnection medium and deterrent for the formation of molecular electromigration and microscopic localized galvanic corrosion.