Preston CMP Material Removal Rate Calculator
Semiconductor thin films & wafer planarization: Model Chemical Mechanical Planarization (CMP) Material Removal Rate (MRR), Preston constant, polishing pad velocity, and WIWNU.
Polisher Kinematics & Film Stack
Material Removal & Planarization Metrics
Recommended Tools & Equipment
Tested hardware and components for high reliability
Frequently Asked Questions
What is copper dishing and dielectric erosion in CMP?
Copper dishing occurs when softer copper in wide metal lines is polished faster than adjacent dielectric, creating a concave recess. Dielectric erosion occurs in dense arrays of narrow metal lines, where high local pressure causes accelerated wear of both copper and oxide barriers.
Why is diamond pad conditioning necessary?
During polishing, pad asperities undergo plastic deformation and slurry reaction byproducts glaze the polyurethane surface, causing MRR to decay. An oscillating diamond-grit conditioner continuously cuts micro-grooves to regenerate pad roughness and restore slurry transport channels.
How is endpoint detection achieved during CMP?
CMP tools monitor endpoint via motor current (detecting the torque change when transitioning from copper to high-friction tantalum barrier), in-situ optical reflectance through a window in the pad, and eddy current sensors that measure remaining metal thickness in real time.