Aluminum-germanium-copper multilevel damascene process using lowtemperature reflow sputtering and chemical mechanical polishing

摘要

A low temperature multilevel aluminum-germanium-copper (Al-Ge-Cu)damascene technology was developed for the first time using reflowsputtering and chemical mechanical polishing (CMP). The maximumprocessing temperature for the fabrication of multilevelinterconnections could be reduced to 420° C using Al-1%Ge0.5%Cu fromconventional reflow temperature of 500° C. No degradation due toreflow heat cycles was observed in Al-Ge-Cu wiring resistance.Electromigration test results indicated that the mean-time-to failure(MTTF) of Al-1%Ge-0.5%Cu was longer than 10 years at the operatingcondition, which is similar to that of Al-1%Si-0.5%Cu. Al-1%Ge-0.5%Cutriple-level interconnection was successfully fabricated by use ofreflow sputtering for filling vias and wiring trenches and successiveCMP