Laboratory for Manufacturing and Sustainability

Local material removal rate is inversely proportional to the local pattern density in ILDCMP. With the assumption that the local velocity and Preston coefficient are constant across a die, local MRR non-uniformity is attributed to the local pressure non-uniformity. Pressure distributions on two different test patterns consisting of five different pattern density sections were calculated with a finite element model. These pressure distributions were compared with semi-empirical pattern dependant oxide CMP model with three different weighting functions. Results showed that pressure distribution can be well approximated with the pattern density dependant oxide CMP model.