Based on the theory of interface migration, a finite-element method is established to
simulate the intragranular microcrack evolution in interconnects induced by
electromigration. The agreement between the finite element solution and
the numerical solution of the thermal grooving confirms the availability of
the finite element method. The calculations show that the intragranular
microcracks have two evolution trends: propagation and shrinkage, and the
microcrack morphology tends to be round in the evolution process. In
the process of microcracks evolution, the linewidth of the interconnects
, the initial aspect
ratio of the microcrack
and the electric field
affect the trend of microcrack evolution, and all of these parameters exist the corresponding
critical values
,
and
. When
,
and
, the
intragranular microcrack shrinks. Otherwise, it propagates. Moreover, the decrease of
the initial aspect ratio, the linewidth or the electric field is conducive to
accelerate microcrack shrinkage. The increase of the initial aspect ratio,
the linewidth or the electric field is conducive to microcrack propagation
conversely.
Keywords
finite element method, interface migration, microcrack
evolution, interconnects, electromigration
