The effect of conditioner aggressiveness is investigated in interlayer dielectric polishing on three types of pad. A method using confocal microscopy is used to analyze the effect of conditioner aggressiveness on pad–wafer contact. Results show that a more aggressive conditioner produces a higher interlayer dielectric polishing rate while at the same time a pad surface with fewer contacting summits and less contact area. It is found that the ratio of the contacting summit density to the contact area fraction is more important than either parameter measured separately since the ratio determines the mean real contact pressure. Modeling results based on contact area measurements agree well with experimental results. Moreover, it is found that a more aggressive disc also generates a thicker slurry film at the pad–wafer interface. This is in agreement with our general findings regarding pad asperity height distribution obtained using confocal microscopy.

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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.

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