Title :
Step like degradation profile of electromigration of W-plug contact
Author :
Qiang, Guo ; Foo, Lo Keng ; Xu, Zeng ; Ping, Neo Soh ; Pei, Yao ; Khiam, Oh Chong
Author_Institution :
Chartered Semicond. Manuf. Ltd., Singapore
Abstract :
The electromigration (EM) of a W-plug contact to silicon has been investigated by high resolution resistance measurement (HRRM). Step-like resistance degradation curves was observed in EM tests. Scanning electron microscope (SEM) observation shows that the number of voids observed in the Al stripe has a good correlation with that of steps in the degradation profile. A new model was developed to associate the microstructure change to the resistance variation. It was found that each step corresponds to one void completely severing the line. We also showed that the interfacial diffusion is a dominant mechanism of bamboo structures in EM measurements
Keywords :
diffusion; electric resistance measurement; electromigration; failure analysis; integrated circuit interconnections; integrated circuit measurement; integrated circuit metallisation; integrated circuit modelling; integrated circuit reliability; scanning electron microscopy; tungsten; voids (solid); Al; Al stripe; EM measurements; EM tests; SEM; W; W-plug contact; bamboo structures; degradation profile steps; electromigration; high resolution resistance measurement; interfacial diffusion; microstructure change; model; resistance variation; scanning electron microscopy; silicon; step like degradation profile; step-like resistance degradation curves; voids; Conductors; Degradation; Electrical resistance measurement; Electromigration; Integrated circuit interconnections; Microstructure; Scanning electron microscopy; Silicon; Temperature; Testing;
Conference_Titel :
Interconnect Technology, 1999. IEEE International Conference
Conference_Location :
San Francisco, CA
Print_ISBN :
0-7803-5174-6
DOI :
10.1109/IITC.1999.787073
