Embodiments of the invention relate generally to measuring conductivity and in particular to a non-contact conductivity measurement with a levitated magnetic rotor system.
Conductivity (or, inversely, resistivity) measurements of materials is routinely needed in many industries such as in semiconductor device fabrication, semiconductor circuit fabrication and various material inspection in manufacturing. Conventional conductivity and resistivity techniques require making contact with a material under test. In some applications, such as in-line process monitoring, it is necessary to have non-contact metrology techniques to measure the conductivity of a material under test due to speed requirements, the presence of insulating layers on the material-under-test or various other reasons.