Rudolph Technologies, Inc.

August Technology Corp.

Rudolph Technology, Inc.

David Vaughnn

Cory Watkins

Mark Harless

Pat Simpkins

Brian Delsey

Shaileshkumar Goyal

Gerald Brown

Alan Blair

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 &#x201c;best-worst&#x201d; image quality. A &#x201c;video focus&#x201d; 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 &#x201c;video focus&#x201d; can be calibrated against the &#x201c;best worst&#x201d; focus. Further, a point sensor can be used to generate a single z-value for one (x,y) location that can be calibrated with &#x201c;video focus&#x201d;.

Focusing method and apparatus

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.

Illuminator for darkfield inspection

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.

Dynamic focusing method and apparatus

An optical throughput condenser re-concentrates light thereby causing light which otherwise would be wasted outside of the useful A&#x3a9; product, also known as optical throughput, of an illuminating system to be redirected back into the useful A&#x3a9; 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 (&#x398;) 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.

Optical throughput condenser

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.

Confocal 3D inspection system and process

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.

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Edina, MN, United States of America

David Vaughnn