Direct relative motion measurement for vibration induced noise and drift cancellation
AssigneeKLA-Tencor Technologies Corporation
InventorsYuval Ben-Dov, Michael Weber-Grabau
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Abstract
A surface analysis apparatus and a method for compensating for mechanical vibrations and drifts in a surface analysis instrument are disclosed. A probe that is sensitive to the distance between the probe and a sample surface provides a probe signal. The probe signal contains information about the surface properties and noise due to changes in the probe-surface distance. A sensor measures a displacement between a probe and the sample surface. The sensor is substantially insensitive to the surface properties measured by the probe. The displacement measurement can be used to compensate for the noise in the probe signal.
Claims25
A surface analysis apparatus, comprising:
- a probe of a type that provides a probe signal that depends on the distance of said probe from a surface of a sample;
- a sensor of a type that produces a sensor signal related to the relative displacement of the probe from the surface of the sample, wherein the sensor is relatively insensitive to properties measured by the probe;
- and
- a processing system adapted to use the sensor signal to compensate for noise in the probe signal whereby the noise in the probe signal will be reduced as a result of the compensation using the sensor signal.
A method for compensating for mechanical vibrations and/or drift in a surface analysis instrument having a probe, the method comprising the steps of:
- measuring a probe signal with the probe, wherein the probe signal depends upon a distance between the probe and a sample surface;
- measuring a sensor signal with a sensor of a type that measures a relative displacement between the probe and the surface of the sample, wherein the sensor is relatively insensitive to properties measured by the probe;
- and
- using said sensor signal to compensate for noise in said probe signal whereby the noise in the probe signal will be reduced as a result of the compensation using the sensor signal.
Dependencies are inferred from the claim text.