Scanning probe microscope having scan correction
AssigneeThe Board of Trustees of the Leland Stanford Junior University
InventorRobert Barrett
Life of this patent
Estimating the term…
Abstract
An atomic force microscope is described having a scan correction arrangement. Sensors detect the actual position of tubular scanners for a sample in an xy plane. This position information is then used for post-imaging correction or as a feedback signal. Detection and use of the actual position assures that errors caused by hysteresis, etc., are obviated. Various embodiments of an appropriate sensor are described.
Claims22
In a scanning probe microscope, the combination comprising:
- a) means for supporting a sample and a probe for relative scanning movement therebetween;
- b) means for sensing a multiple number of times during said relative scanning movement, the position of a portion of said support means along a selected coordinate;
- and
- c) means for responding to said sensing by compensating for any difference between the sensed positions of said portion along said coordinate at the time of said sensings and expected positions of the same therealong.
The scanning probe microscope of any of the previous claims wherein there are two of said coordinates generally orthogonal to one another, said sensing means senses the position of said portion along both of said coordinates, and said responding means compensates for differences along both of said coordinates.
In a scanning probe microscope, the combination comprising:
- a) means for supporting a sample and a probe for relative scanning movement therebetween;
- b) optical-beam position sensing mans for sensing a multiple number of times during said relative scanning movement, the position of a portion of said support means along a selected coordinate;
- said sensing means including a source of optical radiation, a photodetector positioned to receive optical radiation from said source, and radiation flow controlling means for responding to movement of said portion to said position by changing the flow of optical radiation from said source to said photodetector in a manner indicative of said position;
- and
- c) radiation flow controlling means for responding to movement of said portion to said position by changing the flow of optical radiation from said source to said photodetector in a manner indicative of said position.
In a scanning probe microscope, the combination comprising:
- a) a scanner supporting a sample for scanning movement relative to a probe;
- b) optical-beam position sensing means for sensing a multiple number of times during said relative scanning movement, the position of said scanner along a pair of selected orthogonal coordinates;
- said sensing means including for each of said coordinates, a source of optical radiation on one side of its associated coordinate, a photodetector on the opposite side of said coordinate, and a vane secured to said scanner for movement therewith, which vane extends between said source and said photodetector and defines an optical slit in the path of flow of optical radiation between said source and said photodetector to control the flow of optical radiation between said source and said detector in a manner indicative of the position of said scanner along said coordinate;
- and means for responding to said sensing by compensating for any difference between the sensed positions of said portion along each of said coordinates and expected positions of the same therealong upon movement relative to said sensing means along an axis which is generally normal to said coordinate.
Dependencies are inferred from the claim text.