GOALI: ELECTROMIGRATION STUDIES OF ELECTROLESS CU ON SUB-QUARTER-MICRON TEST STRUCTURES

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9709447 Vanasupa The microelectronics industry is currently undergoing a revolution in the technology and material employed to connect individual devices in an integrated circuit (interconnects). It appears that metallizations based on copper will likely replace the aluminum metallizations whose use has dominated the silicon microelectronics industry for decades. Copper offers a lower resistivity as well as a higher resistance to diffusional transport under the influence of high current densities (electromigration). At this point, many of the issues associated with converting to copper metallization have been addressed. With the trend for eversmaller circuits, however, the microelectronics industry is likely to find themselves faced with the same limiting factor currently plaguing the use of aluminum-based metallization: electromigration. The objective of this research is to identify the parameters that are important to preventing electromigration of copper-based metallization in integrated circuits. The objectives will be accomplished by generating a matrix of test samples composed of multiple levels of copper interconnects using an electrochemical process to deposit the copper. The copper deposition parameters will serve as a variable in the experiments since they strongly influence microstructural features of the copper. Samples will be packaged in ceramic daul in-line packages to simulate the operating environment of actual integrated circuits. Electromigration tests will be performed at elevated temperatures until the samples fail. Technics such as focused ion beam microscopy, scanning electron microscopy, secondary ion mass spectrometry and grazing incidence x-ray diffraction will be used to characterize and identify the source of the electromigration failures. ***