Conductive film thickness measurement system based on eddy current sensor and method thereof

Abstract

The invention provides a conductive film thickness measurement system based on an eddy current sensor and a corresponding measurement method. The thickness measurement is realized by using the relation between the slope of an LOC line formed by the corresponding points of the impedance of an eddy current sensor detection coil in a resistance-inductance plane in different detection distances and the thickness of a measured conductive film. The conductive film thickness measurement system comprises an eddy current sensor probe with the detection coil, an impedance measurement circuit, a micro actuator for realizing the vertical movement of the probe, and a controller which controls the measurement process and thickness result output. The method is simple and efficient, the thickness of a conductive film can be accurately measured without contact, the measurement result is nearly not affected by a detection distance, a thickness measurement range is in a range from tens of nanometers to several millimeters, and the method can be widely applied to the semiconductor metal film detection, a metal film online measurement system in an industrial production line and the quality monitoring or detection of various film coating processes.

Description

technical field [0001] The invention relates to the field of eddy current sensors, in particular to a conductive film thickness measurement system and method based on an eddy current sensor. Background technique [0002] The eddy current sensor uses a detection coil with high-frequency excitation to generate an induced eddy current in the measured conductor sample, changing the impedance of the detection coil, different distances and different sample properties will generate different eddy currents, so that the detection coil has different Impedance changes. By measuring the impedance (inductance and resistance) changes of the detection coil, various attribute information such as the position (velocity), resistivity, and thickness of the measured sample can be extracted. Due to the characteristics of the eddy current sensor itself, it has many advantages such as high stability, insensitivity to environmental pollution, wide operating temperature range, wide frequency respon...

AI Technical Summary

Problems solved by technology

However, all these methods still have problems such as complex structure of eddy current sensors, high design requirements, complex signal processing, unreliability, slow measurement speed, and measurement results are affected by the detection distance to a certain extent.

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