Optical metrology with nuisance feature mitigation
AssigneeOnto Innovation Inc.
InventorJonathan Andrew Miller
Life of this patent
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Abstract
A sample that includes a target structure with a structure-of-interest (SOI) having a set of known parameters optically coupled to an unknown structure, e.g., having unknown parameters, is optically measured using light that is incident on the target structure. Light detected from the target structure in response to the incident illumination light incident is used to obtain metrology data, which is a combination of a from the SOI and a contribution from the unknown structure. A set of parameter values characterizing the SOI and a set of parameter values characterizing the unknown structure are determined from a trained neural network based on the metrology data.
Claims22
A method of optical measurement of a sample, the method comprising:
- generating illumination light that is incident on a target structure on the sample, the target structure nominally comprising a combination of a structure-of-interest (SOI) and an unknown structure, the SOI having a set of known parameters comprising nominal structural and material information and the unknown structure having unknown parameters comprising at least one of unknown structural information and unknown material information;
- detecting light from the target structure produced in response to the illumination light that is incident on the target structure;
- obtaining metrology data from the detected light, wherein the metrology data is a combination of a first contribution from the SOI and a second contribution from the unknown structure;
- and
- determining values for the set of known parameters characterizing the SOI as predicted by a trained neural network using the metrology data.
An optical metrology device configured for optical measurement of a sample, the optical metrology device comprising:
- a light source configured to generate light to be incident on a target structure on the sample, the target structure nominally comprising a combination of a structure-of-interest (SOI) and an unknown structure, the SOI having a set of known parameters comprising nominal structural and material information and the unknown structure having unknown parameters comprising at least one of unknown structural information and unknown material information;
- at least one detector configured to detect light from the target structure produced in response to the light that is incident on the target structure;
- and
- at least one processor coupled to the at least one detector, wherein the at least one processor is configured to:
- obtain metrology data from the detected light, wherein the metrology data is a combination of a first contribution from the SOI and a second contribution from the unknown structure;
- and
- determine values for the set of known parameters characterizing the SOI as predicted by a trained neural network using the metrology data.
An optical metrology device configured for optical measurement of a sample, the optical metrology device comprising:
- a light source configured to generate light to be incident on a target structure on the sample, the target structure nominally comprising a combination of a structure-of-interest (SOI) and an unknown structure, the SOI having a set of known parameters comprising nominal structural and material information and the unknown structure having unknown parameters comprising at least one of unknown structural information and unknown material information;
- a detector configured to detect light from the target structure produced in response to the light that is incident on the target structure;
- a means for obtaining metrology data from the detected light, wherein the metrology data is a combination of a first contribution from the SOI and a second contribution from the unknown structure;
- and
- a means for determining values for the set of known parameters characterizing the SOI as predicted by a trained neural network using the metrology data.
Dependencies are inferred from the claim text.