CopperWiring Encapsulation withUltra-thin Barriers toEnhanceWiring and Dielectric Reliabilities for32-nmNodesandBeyond

electro-plating. TheCu-Mnalloy isasource ofMn asa second barrier. After polishing theelectro-plate Cu,we We successfully encapsulated Cuwiring withanultra-thin deposited acapfilm asaCudiffusion barrier ontheinlaid self-forming barrier consisting ofMnO andabi-layer of Cu.Whiledepositing acapfilmatatemperature inexcess MnO/Ta.TDDB testshowedthattheILDslifetime of350°C, MnO segregation occurred attheinterface with increased byafactor of100overthat ofourcontrol sample.theTabarrier inside thetrench andvia, forming asecond Theencapsulated Cuwiring increased EM lifetime bya barrier. MnO segregation alsooccurred attheinterface factor ofmorethan47.Forviachains that arevulnerable to between thecapfilmandinlaid Cu.Thiscompleted the thermal stress, theencapsulated Cuwiring showed noSIV encapsulation. failure. Theresistance oftheencapsulated Cuwiring was 13%lowerthanthatofthecontrol sample. We expectBy applying ultra-thin Ta,we canminimizeMn encapsulated Cuwiring tohavegreater endurance tothe concentration intheseedCu,thereby reducing wiring electrical andthermal stresses forusein32-nmnodesand resistance. Theultra-thin Tabarrier alsostrengthens the