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.

Abstract: A method for enabling more accurate measurements of localized features on wafers is disclosed. The method includes: a) performing high order surface fitting to more effectively remove the low frequency shape components and also to reduce possible signal attenuations commonly observed from filtering; b) constructing and applying a proper two dimensional LFM window to the residual image from the surface fitting processing stage to effectively reduce the residual artifacts at the region boundaries; c) calculating the metrics of the region using the artifact-reduced image to obtain more accurate and reliable measurements; and d) using site-based metrics obtained from front and back surface data to quantify the features of interest. A method for filtering data from measurements of localized features on wafers is disclosed. This method includes an algorithm designed to adjust the filtering behavior according to the statistics of extreme data samples.

Abstract: Disclosed herein is a method to enhance detection and quantification of features in the wafer edge/wafer roll off regions. Modifications and improvements have been made to earlier methods which enable improved accuracy and increased scope of feature detection.

Abstract: A method and system for modeling and analyzing wafer nanotopography data utilizes a nonlinear contact finite element model. Inputs to the model include lithography chuck parameters and site-based geometry data. Outputs from the model include in-plane distortions and out-of-plane distortions, from which defocus and overlay can be derived.

Abstract: This method removes high frequency noise from shape data, significantly improves metrology system (10) performance and provides very compact representation of the shape. This model-based method for wafer shape reconstruction from data measured by a dimensional metrology system (10) is best accomplished using the set of Zernike polynomials (matrix L). The method is based on decomposition of the wafer shape over the complete set of the spatial function. A weighted least squares fit is used to provide the best linear estimates of the decomposition coefficients (Bnk). The method is operable with data that is not taken at regular data points and generates a reduced data field of Zernike coefficients compared to the large size of the original data field.

Abstract: An apparatus for positioning a work piece along a Z-axis includes a base having a depression with an open top in it forming a chamber. A cover member has a rigid central portion and a rigid outer portion coupled with the central portion by an intermediate flexure. The cover member overlies and is secured to the base member at the outer portion of the cover member to close the chamber. Fluid under pressure applied to the chamber is used to move the central portion of the cover member along the Z-axis proportionally to the pressure of fluid applied to the chamber by flexing of the flexure.

Abstract: A method and software is disclosed for evaluating characteristics, such as flatness, of a surface of a sample having an edge, comprising selecting an evaluation area having an area surface and a boundary, at least one portion of which is definable with reference to the edge, and evaluating characteristics of the area surface. Edge-specific evaluation conditions are used with edge-specific metrics to quantify parameters for said evaluation area. A system for evaluating such characteristics comprises a data collection system for generating data values for selected locations on said surface; and a data analyzing system for analyzing data values to determine such characteristics. A data interpolation system may be provided to interpolate data values collected with reference to a first coordinate system for analyzing with reference to a second coordinate system.

Abstract: A ring chuck that holds a wafer with a vacuum uses a vacuum trough that contacts the entire outer edge of the wafer. The chuck has a base having a top surface equal to or slightly smaller than a water to be tested with vacuum channels in the base. The base provides the mechanism to connect the chuck to a measurement instrument and a vacuum source. An annulus of non-contaminant material that has concentric rings extending upward from its outer edge is fixed to the base top surface with the trough between the concentric rings connected to the vacuum channels. The vacuum trough holds the wafer securely to the chuck and minimizes vibrations when the wafer is rotated.

Abstract: An apparatus for measuring semiconductor wafer shape that minimizes wafer distortion. The apparatus includes a plurality of wafer gripping fingers for holding a wafer in a predetermined position during wafer measurement. Each finger includes a groove that contacts the edge of the wafer. The groove and the wafer edge have respective radii of curvature, in which the radius of curvature of the groove is greater than that of the wafer edge. Each finger includes a rigid member having a recess formed in a central location at one end thereof, and a compliant material such as PEEK disposed in the recess in which the groove is formed. The compliant material extends a first distance beyond the rigid member at the central groove location and a second shorter distance beyond the rigid member on each side of the central location.

Abstract: A ring chuck that holds a wafer with a vacuum uses a vacuum trough that contacts the entire outer edge of the wafer. The chuck has a base having a top surface equal to or slightly smaller than a water to be tested with vacuum channels in the base. The base provides the mechanism to connect the chuck to a measurement instrument and a vacuum source. An annulus of non-contaminant material that has concentric rings extending upward from its outer edge is fixed to the base top surface with the trough between the concentric rings connected to the vacuum channels. The vacuum trough holds the wafer securely to the chuck and minimizes vibrations when the wafer is rotated.

Abstract: A method to determine the systematic error of an instrument that measures features of a semiconductor wafer includes the following sequential steps. Collecting sensor data from measurement runs on front and back surfaces of a wafer while the wafer is oriented at different angles to the instrument for each run, yielding a front data set and a back data set for each angle. Then organizing the data in each set into a wafer-fixed coordinate frame. Reflecting all back surface data about a diameter of the wafer creates a reflected back data set. Subtracting the reflected back data from the front data for each wafer angle, and dividing the result by two, yields an averaged wafer shape for each load angle. Adding the reflected back data to the front data and dividing the result by two, yields an instrument signature for each load angle. The symmetric corrector is calculated by taking the average over all instrument signatures at each load angle.

Abstract: A ring chuck that holds a wafer with a vacuum uses a vacuum trough that contacts the entire outer edge of the wafer. The chuck has a base having a top surface equal to or slightly smaller than a wafer to be tested with vacuum channels in the base. The base provides the mechanism to connect the chuck to a measurement instrument and a vacuum source. An annulus of non-contaminant material that has a plurality of concentric rings extending upward from its outer edge is fixed to the base top surface with the trough between the concentric rings connected to the vacuum channels. The vacuum trough holds the wafer securely to the chuck and minimizes vibrations when the wafer is rotated. When the plurality of concentric rings are contained within the wafer exclusion band, the print through onto the tested area is minimized. The tops of the concentric rings are minimally elevated from the top surface of the base and form a sealed volume that supports the interior portion of the wafer.

Abstract: This method removes high frequency noise from shape data, significantly improves metrology system (10) performance and provides very compact representation of the shape. This model-based method for wafer shape reconstruction from data measured by a dimensional metrology system (10) is best accomplished using the set of Zernike polynomials (matrix L). The method is based on decomposition of the wafer shape over the complete set of the spatial function. A weighted least squares fit is used to provide the best linear estimates of the decomposition coefficients (Bnk). The method is operable with data that is not taken at regular data points and generates a reduced data field of Zernike coefficients compared to the large size of the original data field.

Abstract: A ring chuck that holds a wafer with a vacuum uses a vacuum trough that contacts the entire outer edge of the wafer. The chuck has a base having a top surface equal to or slightly smaller than a wafer to be tested with vacuum channels in the base. The base provides the mechanism to connect the chuck to a measurement instrument and a vacuum source. An annulus of non-contaminant material that has a plurality of concentric rings extending upward from its outer edge is fixed to the base top surface with the trough between the concentric rings connected to the vacuum channels. The vacuum trough holds the wafer securely to the chuck and minimizes vibrations when the wafer is rotated. When the plurality of concentric rings are contained within the wafer exclusion band, the print through onto the tested area is minimized. The tops of the concentric rings are minimally elevated from the top surface of the base and form a sealed volume that supports the interior portion of the wafer.

Abstract: A method to determine the systematic error of an instrument that measures features of a semiconductor wafer includes the following sequential steps. Collecting sensor data from measurement runs on front and back surfaces of a wafer while the wafer is oriented at different angles to the instrument for each run, yielding a front data set and a back data set for each angle. Then organizing the data in each set into a wafer-fixed coordinate frame. Reflecting all back surface data about a diameter of the wafer creates a reflected back data set. Subtracting the reflected back data from the front data for each wafer angle, and dividing the result by two, yields an averaged wafer shape for each load angle. Adding the reflected back data to the front data and dividing the result by two, yields an instrument signature for each load angle. The symmetric corrector is calculated by taking the average over all instrument signatures at each load angle.