Accession Number : ADA266391


Title :   Electromigration Characteristics of Copper Interconnects


Corporate Author : CALIFORNIA UNIV BERKELEY DEPT OF ELECTRICAL ENGINEERING AND COMPUTER SCIENCE


Personal Author(s) : Tao, Jiang ; Cheung, Nathan W ; Hu, Chenming


Report Date : May 1993


Pagination or Media Count : 3


Abstract : The electromigration characteristics of electroless plated copper interconnects have been investigated under dc and time-varying current stressing. A novel scheme was reported for selective electroless Cu plating by using 150-A Co as the seeding layer. The Cu dc and pulse-dc lifetimes are found to be one and two orders of magnitude longer than that of Al-4%Cu/ TiW and Al- 2%Si interconnects at 275 deg C, and the extracted Cu lifetime at 75 deg C is about three and five orders of magnitude longer than that of Al-4%Cu/TiW and Al- 2%Si, respectively. As previously reported for Al metallization, the Cu bipolar lifetimes were found to be orders of magnitude longer than their dc lifetimes under the same peak stressing current density because of the partial recovery of electromigration damage during the opposing phases of bipolar stressing


Descriptors :   *LAYERS , *COPPER , *ELECTROLESS PLATING , *SEEDING , STRESSES , REPRINTS , CURRENT DENSITY , PHASE , SILICON , TUNGSTEN , DIOXIDES , METALLIZING , COBALT , BIPOLAR SYSTEMS , DIRECT CURRENT , TITANIUM , ALUMINUM , PULSES , ALLOYS , RECOVERY , DAMAGE


Subject Categories : Metallurgy and Metallography
      Mfg & Industrial Eng & Control of Product Sys
      Electricity and Magnetism


Distribution Statement : APPROVED FOR PUBLIC RELEASE