AFM with referenced or differential height measurement
AssigneeNanoDevices, Inc.
InventorsDennis M. Adderton, Stephen C. Minne
Life of this patent
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Abstract
Thermal drift and acoustic vibrations in the AFM are reduced using a probe-based detection device that references the topography measurement of the AFM to the sample surface in the proximity of the measurement probe. A differential measurement is made between the reference probe and the measurement probe for high sensitivity roughness quantification and defect detection. Multi-probe arrays may be used for large area defect detection with immunity from thermal and acoustic noise sources.
Claims32
An atomic force microscope (AFM) for analyzing a sample, the AFM comprising:
- a mounting platform for supporting the sample;
- a measurement head having a probe assembly;
- and
- a mechanical reference structure for supporting said measurement head and positioning said measurement head generally adjacent to the sample;
- wherein said probe assembly is configured to scan a surface of the sample such that said probe assembly provides two points of measurement and detects a change in the topography of the sample, and wherein said probe assembly is configured to generate a signal indicative of a height difference between said two points of measurement.
A probe-based detection device for an atomic force microscope (AFM), the device comprising:
- a measurement probe and a reference probe which are configured to simultaneously scan a surface of a sample and which both deflect relative to the sample;
- and
- a detector which is coupled to a measurement head of the AFM and which generates a signal indicative of a differential deflection of said probes.
A method of operating a scanning probe microscope (SPM) that detects and stores topography data of a sample surface, the method comprising the steps of:
- scanning the sample surface with a measurement head having a probe-based detection device and a reference measurement device;
- and
- detecting, with said detection device and said reference measurement device, a differential deflection signal in response to a change in the topography of the sample surface.
Dependencies are inferred from the claim text.