Zygo Corporation

Thomas Dresel

Peter J De Groot

Jan Liesener

Generating a composite image of a non-flat surface includes: acquiring, using a microscope, multiple images of different areas of the non-flat surface, where each image includes a region of overlap with at least one adjacent image, the microscope having sufficient resolution to image in three dimensions a microstructure on the non-flat surface having a lateral dimension of 10 microns or less and a height of 10 nm or less; determining, for each of the images, a set of rigid body parameters relating a position and orientation of the test object in the image to a common coordinate system, where the set of rigid body parameters is determined by fitting the resolved microstructure in the overlap region in the image with the corresponding microstructure in the overlap region of the adjacent image; and combining the images based on the sets of rigid body parameters to generate a composite image.

Measuring topography of aspheric and other non-flat surfaces

Methods and systems for measuring asymmetric surface topology are described. In one aspect, a method includes directing a test beam including a spherical wave front along an optical axis to reflect from a test surface; combining the test beam reflected from the test surface with a reference beam to form an interferogram on a detector, where the test and reference beams are derived from a common source; and recording the interferogram for each of multiple lateral displacements of the test surface relative to the optical axis. For each recorded interferogram, the curvature of the spherical wave front at the test surface substantially matches a local curvature of the test surface along a first axis orthogonal to the optical axis, and the multiple lateral displacements of the test surface each include a component along a second axis orthogonal to each of the first axis and the optical axis.

Interferometer and method for measuring non-rotationally symmetric surface topography having unequal curvatures in two perpendicular principal meridians

Interferometric methods and apparatus by which the map between pixel positions and corresponding part locations are determined in situ. The part under test, which is assumed to be a rigid body, is precisely moved from a base position to at least one other position in one to six degrees of freedom in three-dimensional space. Then, the actual displacements are obtained. The base position is defined as the position with the smallest fringe density. Measurements for the base and all subsequent positions are stored. After having collected at least one measurement for each degree of freedom under consideration, the part coordinates are calculated using the differences of the various phase maps with respect to the base position. The part coordinates are then correlated with the pixel coordinates and stored.

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Nuremberg, Germany

Thomas Dresel