Provided are materials and methods for the chemical mechanical planarization
of material layers using a down force of less than about 2.5 psi while maintaining
a material removal rate generally similar to that obtained using higher down forces
while simultaneously improving the selectivity of the process with respect to a
primary material formed over a barrier material. The materials and methods disclosed
herein are suitable for use in meatallization operations during semiconductor device
fabrication, in particular in processes in which the primary material is a softer
metal such as copper and the barrier material is a harder material such as a metal nitride.
