Patent ID: 7830141
Filing Date: 2010-11-09
Classification: G01B

Abstract:
1. A film thickness measuring method for measuring a film thickness of a conductive film formed on a substrate, the film thickness measuring method comprising the steps of: making one coil be opposed to a surface of the conductive film; making a magnetic field made to be induced in the coil by an alternating current supplied to the coil operate on the conductive film; increasing an eddy current induced in the conductive film by increasing a frequency of the alternating current in a state a magnetic flux infiltrates the conductive film; decreasing the eddy current induced in the conductive film by further increasing the frequency to decrease the magnetic flux penetrating through the conductive film due to a skin effect determined with a material of the conductive film as a factor; and finding a film thickness of the conductive film based on a frequency at a changing point of the eddy current induced in the conductive film in the increasing step and the decreasing step.