After chemical mechanical polishing (CMP) of oxides became a standard
method for global planarization, the polishing of metals is now being
embraced by manufacturing. Although tungsten CMP has been used for sub
half-micron technologies for quite some time, there is still a lack of
theoretical understanding and modeling of the metal CMP processes. Th
is paper presents a mathematical approach to describe erosion and dish
ing for tungsten CMP. The model, which represents the pad by a network
of springs, simulates the profile of a dished tungsten line. The calc
ulated data are then compared with experimental data.