Abstract: Methods and apparatus for placing wafers axially in an optical inspection system. A “best worst” focus method includes a series of through-focus images of a test wafer acquired using full field of view of the inspection optics. The value of the worst quality in each image is associated with the respective axial location, forming a locus of “worst” values as a function of axial location. The axial location is chosen which optimizes the locus, giving an axial location that provides the “best-worst” image quality. A “video focus” method includes a series of through-focus images generated using reduced field of view. A figure of merit is associated with each image, providing through-focus information. The “video focus” can be calibrated against the “best worst” focus. Further, a point sensor can be used to generate a single z-value for one (x,y) location that can be calibrated with “video focus”.

Abstract: Methods and apparatus for placing wafers axially in an optical inspection system. A “best worst” focus method includes a series of through-focus images of a test wafer acquired using full field of view of the inspection optics. The value of the worst quality in each image is associated with the respective axial location, forming a locus of “worst” values as a function of axial location. The axial location is chosen which optimizes the locus, giving an axial location that provides the “best-worst” image quality. A “video focus” method includes a series of through-focus images generated using reduced field of view. A figure of merit is associated with each image, providing through-focus information. The “video focus” can be calibrated against the “best worst” focus. Further, a point sensor can be used to generate a single z-value for one (x,y) location that can be calibrated with “video focus”.

Abstract: A reflective objective is disclosed, in which essentially all the optical power is in a single, off-axis, concave mirror, which is oriented generally perpendicular to the central axis of the objective. An incident beam is directed to and from the concave mirror by a pair of flat mirrors, so that a central on-axis ray in the incident beam is collinear with the corresponding thrice-reflected ray at the object. The object is one focal length away from the concave mirror. The aperture stop is also one focal length away from the concave mirror, leading to a condition of telecentricity at the object. Different focal lengths for the objectives are realized by using mirrors with different curvatures, located at different distances away from the central axis of the objective. The reflective objective can optionally be retrofitted into a turret typically used for microscope objectives, and can optionally have refractive elements, making the objective catadioptric.

Abstract: Light from a single source is divided among several illumination arms, each of which directs light via a multimode fiber bundle from the source to the wafer location. The arms are arranged circumferentially around a common illumination region, so that the region is illuminated from several directions. For each arm, light exiting the fiber bundle enters a turning prism, reflects off the hypotenuse of the prism, and is diverged in one dimension by a negative cylindrical surface on the exiting face of the prism. The beam then reflects off an anamorphic mirror and propagates to the illumination region on the wafer. The beam has an asymmetric footprint, so that it illuminates a nearly circular region of the wafer when viewed at normal incidence. The fiber bundle is at the front focal plane in the meridional dimension. The illumination region is at the rear focal plane in both dimensions.

Abstract: Light from a single source is divided among several illumination arms, each of which directs light via a multimode fiber bundle from the source to the wafer location. The arms are arranged circumferentially around a common illumination region, so that the region is illuminated from several directions. For each arm, light exiting the fiber bundle enters a turning prism, reflects off the hypotenuse of the prism, and is diverged in one dimension by a negative cylindrical surface on the exiting face of the prism. The beam then reflects off an anamorphic mirror and propagates to the illumination region on the wafer. The beam has an asymmetric footprint, so that it illuminates a nearly circular region of the wafer when viewed at normal incidence. The fiber bundle is at the front focal plane in the meridional dimension. The illumination region is at the rear focal plane in both dimensions.

Abstract: Methods and apparatus for placing wafers axially in an optical inspection system. A “best worst” focus method includes a series of through-focus images of a test wafer acquired using full field of view of the inspection optics. The value of the worst quality in each image is associated with the respective axial location, forming a locus of “worst” values as a function of axial location. The axial location is chosen which optimizes the locus, giving an axial location that provides the “best-worst” image quality. A “video focus” method includes a series of through-focus images generated using reduced field of view. A figure of merit is associated with each image, providing through-focus information. The “video focus” can be calibrated against the “best worst” focus. Further, a point sensor can be used to generate a single z-value for one (x,y) location that can be calibrated with “video focus”.

Abstract: A method and apparatus for dynamically focusing an imaging mechanism on a moving target surface having a variable geometry is herein disclosed. Apparatus for focusing an imaging mechanism may include an objective, a prism, or another optical device that forms part of an optical train of an imaging mechanism, a sensor for measuring a distance to the target surface, and a mechanism for modifying the depth of focus of the objective, prism or other optical device. Data from the sensor may be used to create a predictive model of the target surface. Data from the sensor is also used to fit or correlate the generated model to an exemplary target. Data from the correlated model is used to drive the mechanism for modifying the depth of focus of the objective, prism, or other optical device to maintain the surface of the exemplary target in focus.

Abstract: A reflective objective is disclosed, in which essentially all the optical power is in a single, off-axis, concave mirror, which is oriented generally perpendicular to the central axis of the objective. An incident beam is directed to and from the concave mirror by a pair of flat mirrors, so that a central on-axis ray in the incident beam is collinear with the corresponding thrice-reflected ray at the object. The object is one focal length away from the concave mirror. The aperture stop is also one focal length away from the concave mirror, leading to a condition of telecentricity at the object. Different focal lengths for the objectives are realized by using mirrors with different curvatures, located at different distances away from the central axis of the objective. The reflective objective can optionally be retrofitted into a turret typically used for microscope objectives, and can optionally have refractive elements, making the objective catadioptric.

Abstract: A method and apparatus for dynamically focusing an imaging mechanism on a moving target surface having a variable geometry is herein disclosed. Apparatus for focusing an imaging mechanism may include an objective, a prism, or another optical device that forms part of an optical train of an imaging mechanism, a sensor for measuring a distance to the target surface, and a mechanism for modifying the depth of focus of the objective, prism or other optical device. Data from the sensor may be used to create a predictive model of the target surface. Data from the sensor is also used to fit or correlate the generated model to an exemplary target. Data from the correlated model is used to drive the mechanism for modifying the depth of focus of the objective, prism, or other optical device to maintain the surface of the exemplary target in focus.

Abstract: A method and apparatus for dynamically focusing an imaging mechanism on a moving target surface having a variable geometry is herein disclosed. Apparatus for focusing an imaging mechanism may include an objective, a prism, or another optical device that forms part of an optical train of an imaging mechanism, a sensor for measuring a distance to the target surface, and a mechanism for modifying the depth of focus of the objective, prism or other optical device. Data from the sensor may be used to create a predictive model of the target surface. Data from the sensor is also used to fit or correlate the generated model to an exemplary target. Data from the correlated model is used to drive the mechanism for modifying the depth of focus of the objective, prism, or other optical device to maintain the surface of the exemplary target in focus.

Abstract: An optical throughput condenser re-concentrates light thereby causing light which otherwise would be wasted outside of the useful A? product, also known as optical throughput, of an illuminating system to be redirected back into the useful A? product. The optical throughput condenser includes a thin film having an angle gate such that light striking the surface with a range of incident angles such that the angle of incident is less than or equal to the gate angle (?GATE) transmits through the thin film. Light striking the surface with a range of incident angles such that the angle of incident is grater than the gate angle. reflects back from the thin film. An integrating sphere is positioned such that light reflecting back from the thin film is directed towards the integrating sphere so that the light is redirected towards the angle gate.

Abstract: An imaging system for capturing images of a tilted object includes a lens having an optical axis, a detector array, and a normalizer positioned between the lens and a detector array for realigning light passing therethrough such that the Scheimmpflug condition with respect to the tilted object being imaged is satisfied and light is incident upon the detector array in a substantially normal orientation.

Abstract: A method and apparatus for dynamically focusing an imaging mechanism on a moving target surface having a variable geometry is herein disclosed. Apparatus for focusing an imaging mechanism may include an objective, a prism, or another optical device that forms part of an optical train of an imaging mechanism, a sensor for measuring a distance to the target surface, and a mechanism for modifying the depth of focus of the objective, prism or other optical device. Data from the sensor may be used to create a predictive model of the target surface. Data from the sensor is also used to fit or correlate the generated model to an exemplary target. Data from the correlated model is used to drive the mechanism for modifying the depth of focus of the objective, prism, or other optical device to maintain the surface of the exemplary target in focus.

Abstract: Aspects of the present invention relate to a camera module for use in an optical inspection system. The camera module includes a beamsplitter assembly, a first detector assembly, and a second detector assembly. The beamsplitter assembly defines orthogonally arranged first and second sides that are optically separated by a beamsplitter face. The first detector assembly includes a detector array for sensing an image. The first detector assembly is associated with the first side of the beamsplitter assembly. The second detector assembly similarly includes a detector array for sensing an image. The second detector assembly is associated with the second side of the beamsplitter. Further, the first and second detector assemblies are substantially optically aligned relative to the beamsplitter assembly.

Abstract: Light from a single source is divided among several illumination arms, each of which directs light via a multimode fiber bundle from the source to the wafer location. The arms are arranged circumferentially around a common illumination region, so that the region is illuminated from several directions. For each arm, light exiting the fiber bundle enters a turning prism, reflects off the hypotenuse of the prism, and is diverged in one dimension by a negative cylindrical surface on the exiting face of the prism. The beam then reflects off an anamorphic mirror and propagates to the illumination region on the wafer. The beam has an asymmetric footprint, so that it illuminates a nearly circular region of the wafer when viewed at normal incidence. The fiber bundle is at the front focal plane in the meridional dimension. The illumination region is at the rear focal plane in both dimensions.

Abstract: A confocal three dimensional inspection system, and process for use thereof, allows for inspecting of bumps and other three dimensional (3D) features on wafers and other semiconductor substrates. The sensor eliminates out of focus light using a confocal principal to improve depth response.

Abstract: A confocal three dimensional inspection system, and process for use thereof, allows for rapid inspecting of bumps and other three dimensional (3D) features on wafers, other semiconductor substrates and other large format micro topographies. The sensor eliminates out of focus light using a confocal principal to create a narrow depth response in the micron range.

Abstract: A confocal three dimensional inspection system, and process for use thereof, allows for rapid inspecting of bumps and other three dimensional (3D) features on wafers, other semiconductor substrates and other large format micro topographies. The sensor eliminates out of focus light using a confocal principal to create a narrow depth response in the micron range.

Abstract: An optical throughput condenser re-concentrates light thereby causing light which otherwise would be wasted outside of the useful A&OHgr; product, also known as optical throughput, of an illuminating system to be redirected back into the useful A&OHgr; product. The optical throughput condenser includes a thin film having an angle gate such that light striking the surface with a range of incident angles such that the angle of incident is less than or equal to the gate angle (&THgr;GATE) transmits through the thin film. Light striking the surface with a range of incident angles such that the angle of incident is grater than the gate angle. reflects back from the thin film. An integrating sphere is positioned such that light reflecting back from the thin film is directed towards the integrating sphere so that the light is redirected towards the angle gate.

Abstract: A confocal three dimensional inspection system, and process for use thereof, allows for inspecting of bumps and other three dimensional (3D) features on wafers and other semiconductor substrates. The sensor eliminates out of focus light using a confocal principal to improve depth response.