Near-field scanning optical microscope using a fluorescent probe
AssigneeAT&T Bell Laboratories
InventorsRobert E. Betzig, Jay K. Trautman
Life of this patent
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Abstract
A novel probe, useful for near-field optical scanning microscopy, is provided. The probe has a fine tip which includes fluorescent material. In one embodiment, the invention is an apparatus which includes such a probe, means for exciting and detecting fluorescence in the probe tip, means for positioning the probe tip near the surface of a sample, and means for displacing the probe tip relative to the sample. In a second embodiment, the invention is a manufacturing method in which the novel probe is used to measure a characteristic dimension of a patterned workpiece.
Claims11
In a near-field scanning optical microscope, apparatus comprising:
- a probe, the probe having a tip capable of emitting light at least at a given wavelength;
- means for detecting at least a portion of the light emitted by the probe tip;
- means for positioning the probe adjacent a sample such that the distance between the probe tip and the sample is smaller than about five times the given wavelength;
- and
- means for displacing the probe tip relative to the sample,
- CHARACTERIZED IN THAT
- the probe tip comprises fluorescent material capable of emitting light at least at the given wavelength when the fluorescent material is appropriately excited;
- and
- the apparatus further comprises means for exciting the fluorescent material.
Method for manufacturing an article, comprising the steps of:
- a) providing a multiplicity of semiconductor wafers, each wafer having a surface to be patterned by means of a patterning process;
- b) setting at least one parameter of the patterning process;
- c) processing at least a first wafer according to the process parameter, such that a pattern is formed on the surface of the wafer, the pattern having a characteristic dimension;
- d) measuring the characteristic dimension in at least one of the multiplicity of semiconductor wafers;
- e) comparing the characteristic dimension to a predetermined range of values;
- f) if the characteristic dimension lies outside the predetermined range of values, changing the process parameter to bring the characteristic dimension within the predetermined range of values;
- g) after (f), processing at least a second wafer according to the process parameter;
- and
- h) performing, on at least the second wafer, at least one additional step toward completion of the article,
- CHARACTERIZED IN THAT
- the measuring step comprises:
- i) providing a probe having a tip, the probe tip comprising fluorescent material capable of emitting light at least at a given wavelength when the fluorescent material is appropriately excited;
- j) positioning the probe relative to the wafer such that the distance between the probe tip and at least a portion of the pattern is smaller than the given wavelength;
- k) displacing the probe tip relative to the wafer;
- l) during the displacing step, exciting fluorescence in the probe tip;
- and
- m) detecting fluorescent light emitted by the probe tip.
Dependencies are inferred from the claim text.