Challenge

Copper CMP, an integral part of Dual Damascene, planarizes the relatively soft metal film to a target thickness, leaving behind a smooth uniform surface, free of defects. Metal softness, varying line densities, and porous low-k dielectrics pose challenges to copper CMP, where imperfections such as copper dishing and dielectric erosion can degrade device performance and reduce yield. Tight process control is, thus, required to ensure specified dielectric and copper line thicknesses and residue-free layers.

Solutions

Nova is the industry leader in CMP process control. Nova’s metrology solutions provide precise measurement of copper line thickness, dishing, erosion and metal residues. The high accuracy of Nova’s metrology enables closed loop control solutions for copper CMP, allowing higher CMP throughput coupled with high yield. Nova’s Integrated Metrology (IM) delivers high sampling rates of up to 200 WPH, while allowing the measurement of copper line thicknesses. When lot-to-lot control is required, Nova’s Standalone metrology provides a cost effective solution with throughput of up to 150 WPH and industry-leading fleet (tool-to-tool) matching.

With the smaller geometries of next generation designs, Nova’s metrology measurements are not restricted to solid pads, but can also be made on 2D and 3D test structures as well as in-die.