Corrosion Resistance of Several Integrated-Circuit Metallization Systems

Accelerated life data are presented on several integratedcircuit metallization systems including Al, Mo-Au, Ti-Pt-Au, and a new system Ti: W-Au where the RF sputtered Ti: W layer is a pseudo alloy of 10-20 percent Ti in W. Life tests include total water immersion, high-pressure steam and 85°C/85 percent RH/bias on bare and plastic-encapsulated devices. Heat-age and resistivity-ratio data are presented showing the metallurgical stability of the Ti: W-Au system. The corrosion resistance decreases as Ti-Pt-Au > Ti: W-Au >> Mo-Au ¿ Al.