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US 9,177,370 B2Granted
Systems and methods of advanced site-based nanotopography for wafer surface metrology
AssigneeKLA-Tencor Corporation
InventorsHaiguang Chen, Sergey Kamensky, Jaydeep Sinha, Pradeep Vukkadala
Life of this patent
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Abstract
Systems and methods for providing micro defect inspection capabilities for optical systems are disclosed. Each given wafer image is filtered, treated and normalized prior to performing surface feature detection and quantification. A partitioning scheme is utilized to partition the wafer image into a plurality of measurement sites and metric values are calculated for each of the plurality of measurement sites. Furthermore, transformation steps may also be utilized to extract additional process relevant metric values for analysis purposes.
Claims52
A method for inspecting a wafer, comprising:
- defining a wafer partitioning scheme;
- obtaining a wafer surface image;
- filtering the wafer surface image to remove a low frequency surface components;
- performing wafer edge treatment on the wafer surface image to suppress a strong filter response from a sharp wafer edge roll-off or data discontinuity created by edge exclusion operation;
- normalizing filter response present on the wafer surface image;
- partitioning the wafer surface image into a plurality of measurement sites according to the wafer partitioning scheme;
- calculating a metric value for each of the plurality of measurement sites based on the filtered wafer surface image;
- and
- reporting the metric value calculated for each of the plurality of measurement sites in a graphical representation.
6 more elements
A method for inspecting a wafer, comprising:
- defining a wafer partitioning scheme;
- obtaining a wafer surface image;
- filtering the wafer surface image to remove a low frequency surface components;
- performing wafer edge treatment on the wafer surface image to suppress a strong filter response from a sharp wafer edge roll-off or data discontinuity created by edge exclusion operation;
- normalizing filter response present on the wafer surface image;
- partitioning the wafer surface image into a plurality of measurement sites according to the wafer partitioning scheme;
- performing at least one of:
- Fourier transform, Cosine transform, or wavelet transform on each of the plurality of measurement sites;
- calculating a metric value for each of the plurality of measurement sites based on the transformed wafer surface image;
- and
- reporting the metric value calculated for each of the plurality of measurement sites in a graphical representation.
8 more elements
A wafer inspection system, comprising:
- an optical system configured for obtaining a wafer surface image of the given wafer;
- and
- a site based measurement module in communication with the optical system, the site based measurement module configured for:
- receiving a wafer partitioning scheme;
- filtering the wafer surface image to remove a low frequency surface components;
- performing wafer edge treatment on the wafer surface image to suppress a strong filter response from a sharp wafer edge roll-off or data discontinuity created by edge exclusion operation;
- normalizing filter response present on the wafer surface image;
- partitioning the wafer surface image into a plurality of measurement sites according to the wafer partitioning scheme;
- calculating a metric value for each of the plurality of measurement sites based on the filtered wafer surface image;
- and
- reporting the metric value calculated for each of the plurality of measurement sites in a graphical representation.
8 more elements
A wafer inspection system, comprising:
- an optical system configured for obtaining a wafer surface image of the given wafer;
- and
- a site based measurement module in communication with the optical system, the site based measurement module configured for:
- receiving a wafer partitioning scheme;
- filtering the wafer surface image to remove a low frequency surface components;
- performing wafer edge treatment on the wafer surface image to suppress a strong filter response from a sharp wafer edge roll-off or data discontinuity created by edge exclusion operation;
- normalizing filter response present on the wafer surface image;
- partitioning the wafer surface image into a plurality of measurement sites according to the wafer partitioning scheme;
- performing at least one of:
- Fourier transform, Cosine transform, or wavelet transform on each of the plurality of measurement sites;
- calculating a metric value for each of the plurality of measurement sites based on the transformed wafer surface image;
- and
- reporting the metric value calculated for each of the plurality of measurement sites in a graphical representation.
10 more elements
Dependencies are inferred from the claim text.