C.-K. Hu, L. Gignac, et al.
JES
An in situ electromigration apparatus was used to study the kinetics of void growth in unpassivated, electropolated copper damascene lines. Voids were observed to grow by consuming grains in a stepwise fashion, either by grain thinning or by an edge displacement mechanism. Surface diffusion was found to be the primary diffusion path for void growth. In addition, grain boundaries provided a secondary path for copper diffusion in polycrystalline structures and nucleation sites for void growth in bamboo structures. Void growth rate was measured as a function of sample temperature and linewidth using a scanning electron microscope. An electromigration activation energy of 0.9±0.1 eV was determined for the copper voiding process. The effect of linewidth on void growth rate was also investigated and found to be negligible, consistent with a surface-diffusion dominated model for void growth. The in situ apparatus also made it possible to directly correlate changes in electrical resistance with physical changes taking place in the test structures. © 2002 American Institute of Physics.
C.-K. Hu, L. Gignac, et al.
JES
B.N. Agarwala, D. Nguyen, et al.
ECS Meeting 2005
T.M. Shaw, E. Liniger, et al.
IITC 2007
K.W. Guarini, C.T. Black, et al.
IEDM 2003