Pad porosity, compressibility and slurry delivery effects in chemical-mechanical planarization: modeling and experiments

• Published in: Thin solid films Vol. 366; no. 1; pp. 181 - 190
• Main Authors: Thakurta, Dipto G, Borst, Christopher L, Schwendeman, Donald W, Gutmann, Ronald J, Gill, William N
• Format: Journal Article
• Language: English
• Published: Lausanne Elsevier B.V 01.05.2000; Elsevier Science
• Subjects: Applied sciences; Chemical mechanical planarization; Electronics; Exact sciences and technology; Lubrication model; Mechanical engineering. Machine design; Metallization, contacts, interconnects; device isolation; Microelectronic fabrication (materials and surfaces technology); Polish pad properties; Precision engineering, watch making; Semiconductor electronics. Microelectronics. Optoelectronics. Solid state devices; Wafer scale model; Lubrication model; Wafer scale model; Chemical mechanical planarization; Polish pad properties; Microelectronic fabrication; Planarization; Mechanical polishing; Precision engineering; Chemical polishing; Two dimensional model; Lubrication; Particle suspension; Experimental study; Modeling; Wafer
• ISSN: 0040-6090; 1879-2731
• DOI: 10.1016/S0040-6090(00)00748-3

A chemical-mechanical planarization (CMP) model based on lubrication theory is developed which accounts for pad compressibility, pad porosity and means of slurry delivery. Slurry film thickness and velocity distributions between the pad and the wafer are predicted using the model. Two regimes of CMP operation are described: the lubrication regime (for ∼40–70 μm slurry film thickness) and the contact regime (for thinner films). These regimes are identified for two different pads using experimental copper CMP data and the predictions of the model. The removal rate correlation based on lubrication and mass transport theory agrees well with our experimental data in the lubrication regime.