Patent ID: 9528814
Filing Date: 2016-12-27
CPC Classification: B24B,G01B

Claim Text:
1. An apparatus for measuring film thickness on an underlying body comprising at least one Impedance Resonance (IR) sensor comprising the following: at least one sensing head which is an open core or coreless (air core) inductor comprising at least one excitation coil and at least one sensing coil, wherein: (i) said excitation coil is intended to propagate an energy to the sensing coil, which is intended to generate a probing electromagnetic field; (ii) said at least one sensing coil is designed in such a way that intrinsic inductance L, capacitance C, and resistance R parameters of said sensing coil are capable of providing resonance conditions within predetermined frequency range for measuring impedance of wafer (or substrate) part falling within the scope of the sensor's sensitive area; and (iii) said at least one sensing coil is not connected to any capacitance means located externally to said at least one sensing coil such that said at least one sensing coil is capable of measuring one or more properties of said wafer (or substrate) part; at least one power supply; at least one RF sweep generator electrically connected to said excitation coil; at least one data acquisition block with a high impedance input, greater than 10 MΩ electrically connected to both the excitation coil and the sensing coil of the sensor; at least one calculation block; and at least one communication block.