Abstract: A method for measuring conductance of a sample using an eddy current probe with a sensing coil. The method includes N repetitions of measuring first and second voltage pairs including in-phase and quadrature components of an induced AC voltage in the sensing coil, calibrating the first signal based on the measured second signal at a different separation from the sample and reference material, determining a conductance function relating conductance with location along the selected curve, processing the calibrated first voltage pairs to generate a lift-off curve, determining an intersection voltage pair representing intersection of the lift-off curve with a selected curve, and determining the conductance of the sample from the intersection voltage pair and the conductance function.

Abstract: A method for measuring conductance of a sample using an eddy current probe with a sensing coil. The method includes N repetitions of measuring first and second voltage pairs including in-phase and quadrature components of an induced AC voltage in the sensing coil, calibrating the first signal based on the measured second signal at a different separation from the sample and reference material, determining a conductance function relating conductance with location along the selected curve, processing the calibrated first voltage pairs to generate a lift-off curve, determining an intersection voltage pair representing intersection of the lift-off curve with a selected curve, and determining the conductance of the sample from the intersection voltage pair and the conductance function.

Abstract: Disclosed is a chemical mechanical polishing (CMP) system for polishing a sample with a polishing agent and monitoring the sample. The CMP system includes a polishing table, a sample carrier arranged to hold the sample over the polishing table, and an eddy probe. The polishing table and sample carrier are arranged to receive a polishing agent between the sample and the polishing table and to polish the sample by moving the polishing table and the sample carrier relative to each other. The eddy probe is arranged to be operable to obtain a measurement of the sample while the sample is being polished. The CMP system further includes an optical measurement device arranged to be operable to obtain a measurement of the sample while the sample is being polished. The CMP system also has a memory and a processor coupled with the memory. The processor and memory are adapted for operating the eddy probe and optical measurement device.

Abstract: A method for measuring conductance of a sample using an eddy current probe with a sensing coil. The method includes N repetitions of measuring first and second voltage pairs including in-phase and quadrature components of an induced AC voltage in the sensing coil, calibrating the first signal based on the measured second signal at a different separation from the sample and reference material, determining a conductance function relating conductance with location along the selected curve, processing the calibrated first voltage pairs to generate a lift-off curve, determining an intersection voltage pair representing intersection of the lift-off curve with a selected curve, and determining the conductance of the sample from the intersection voltage pair and the conductance function.

Abstract: Disclosed is a method of obtaining information in-situ regarding a film of a sample using an eddy probe during a process for removing the film. The eddy probe has at least one sensing coil. An AC voltage is applied to the sensing coil(s) of the eddy probe. One or more first signals are measured in the sensing coil(s) of the eddy probe when the sensing coil(s) are positioned proximate the film of the sample. One or more second signals are measured in the sensing coil(s) of the eddy probe when the sensing coil(s) are positioned proximate to a reference material having a fixed composition and/or distance from the sensing coil. The first signals are calibrated based on the second signals so that undesired gain and/or phase changes within the first signals are corrected. A property value of the film is determined based on the calibrated first signals. An apparatus for performing the above described method is also disclosed.