| 摘要 |
In one embodiment, a sample is tested by an eddy current sensor at two distances separated by a known incremental distance. In one aspect, at least one of an unknown distance of the sensor from the test sample and the film thickness of the test sample may be determined as a function of a comparison of sensor output levels of a single parameter and the known incremental distance to calibration data. In yet another aspect, the distance between the sensor and the test sample may oscillated to produce an oscillating sensor output signal having an amplitude and mean which may be measured and compared to calibration data to identify at least one of the unknown film thickness of a conductive film on a test sample, and the unknown distance of the test sample from the sensor. Other aspects and features are also described. |
