In chemical mechanical planarization (CMP), Stribeck curves are normally constructed by plotting average coefficient of frictions (COF) against the average Sommerfeld number. Consequently, traditional Stribeck curves fail to provide a full explanation of the lubrication phenomena simply because COF and polishing downforce can fluctuate significantly due to stick-slip phenomena and transient instabilities caused by polishing kinematics and consumables. This study introduces a new method for rapidly generating an "improved" Stribeck curve (i.e. Stribeck+ curve) that shows a more complete tribological picture of the process. The method significantly reduces the consumables and time required to obtain the curve compared to traditional means. Results of the Stribeck+ curve are consistent with individual tests using several different consumables combinations. All copper CMP Stribeck+ examples clearly indicate the lubrication mechanism and transitions thereof between different polishing conditions. Variability in COF as well as a much wider range in v/P are also explored.
- Chemical mechanical planarization
- Coefficient of frictions
- Lubrication mechanism
- Stribeck+ curve
ASJC Scopus subject areas
- Electronic, Optical and Magnetic Materials