General Electric Company

Hermes Microvision Inc.

Van-Duc Nguyen

Victor Nzomigni

Joe Wang

Charles Vernon Stewart

Jack Jau

Chiyan Kuan

Joseph Leagrand Mundy

Yi-Xiang Wang

Donald Wagner Hamilton

Jian Zhang

Zhongwei Chen

Zhong-wei Chen

Glen William Brooksby

Steven Jeffrey Gordon

John L Schneiter

Joseph Benjamin Ross

Yi Xiang Wang

Faycal Benayad-Cherif

Roderic Greene Collins

Nathalie Claire Poirier

Lila Abdessemed

Kishore Bubna

Thomas Watkins Lloyd, Jr

This invention relates to methods and systems for enhance the signal-to-noise ratio of an image scanned by a charged particle beam. In an embodiment, a sequence of grayscales of a pixel is recorded first, extreme values of the sequence of grayscales are then identified and removed, and the remained grayscales are used to determine a nominated grayscale of the pixel.

Method and system for enhancing image quality

The present invention generally relates to dynamic focus adjustment for an image system. With the assistance of a height detection sub-system, present invention provides an apparatus and methods for micro adjusting an image focusing according the specimen surface height variation by altering the field strength of an electrostatic lens between objective lens and sample stage/or a bias voltage applied to the sample surface. Merely by way of example, the invention has been applied to a scanning electron inspection system. But it would be recognized that the invention could apply to other system using charged particle beam as observation tool with a height detection apparatus.

Dynamic focus adjustment with optical height detection apparatus in electron beam system

A method and system for inspecting a semiconductor wafer. The method includes providing an illumination flux through a pattern plate and a lens to a surface of a specimen to project a pattern onto the surface of the specimen. The pattern is associated with the pattern plate. Additionally, the method includes detecting the illumination flux reflected from the surface of the specimen with a detector, processing information associated with the detected illumination flux, and generating a first image based on at least information associated with the detected illumination flux. The first image includes a first image part for the pattern and a second image part for the specimen. Moreover, the method includes adjusting the lens to a state in order to achieve a first predetermined quality for the first image part, and moving the specimen to a first position.

Optical auto focusing system and method for electron beam inspection tool

A non-contact imaging apparatus for examining an object having complex surfaces or shape deformations. The imaging apparatus includes at least one imaging device for obtaining a scanned image of the exterior surfaces of the object being examined. A predetermined reference image) of an ideal model for the object is stored in a memory. An image register is coupled to the imaging device and to the memory containing the reference image of the ideal model for the object. A transformation estimator compares the scanned image to the reference image and provides a transform which maps the scanned image to the reference image and provides a set of registered object data points. One or more filter modules process the registered object data points with a priori information to reduce noise and to further enhance the accuracy and precision of the registration. A gauge estimator is coupled to the filter module. The gauge estimator utilizes the processed and registered object data to determine deformation parameters of the object, which are then displayed to an operator as gauging information.

Non-contact measurement method and apparatus

The present invention is directed to an imaging apparatus for examining an object having smooth surfaces to determine shape deformations in the surface of object. The imaging apparatus includes an imaging device for obtaining a scanned image of the object to be examined. A reference image of the object is stored in a memory. An image register is coupled to the imaging device and to the memory containing the reference image of the object. The image register stores patch information corresponding to both the reference image and the scanned image. A transformation estimator is coupled to the image register, and provides a transform for registering the scanned image to the reference image. A deformation estimator is coupled to the transformation estimator and to the image register. The deformation estimator is configured to utilize the transform and the patch information to determine shape deformations of the object.

Method and apparatus for finding shape deformations in objects having smooth surfaces

A machine vision system includes an apparatus for registering an input image of an object, such as an aircraft engine blade, to a reference image comprising ideal specifications for the object in order to detect flaws in the object. The system includes one or more imaging devices for obtaining the input image representing the object. The system further includes a processor for registering the input image to the reference image. The processor includes a patch determining device for identifying low curvature portions of the reference image off-line. A transformation estimator matches the low curvature portions of the reference image to corresponding low curvature portions of the object, and provides a transformation matrix which maps points on the reference image to corresponding points on the input image for precise and fast registration.

Method and apparatus for image registration

A method for calibrating a non-contact range sensor comprises the steps of employing the range sensor to obtain a range image of an object to be inspected. The range image is registered with a reference image of the object thereby providing registered data. The reference image may be derived through computer assisted drawing (CAD) data. Normal deviations between the registered data and the reference image are computed. Noise is filtered from the normal deviations. A plurality of bias vectors and a covariance matrix are estimated based on the normal deviations, stored in memory as a lookup table comprising geometric correction factors for the sensor. Images of the object subsequently obtained by the sensor are compensated in accordance with the lookup table.

Method and apparatus for calibrating a non-contact range sensor

A method of detecting abnormalities including a learning phase and an inspection phase. In the learning phase, a first statistical quantity and a second statistical quantity are determined based on a first set of n-dimensional data. A second set of n-dimensional data is obtained and a bimodal distribution for a plurality of n-dimensional points in each of the second set of n-dimensional data is determined. A reference template is generated in response to the first statistical quantity, second statistical quantity and bimodal distribution. In the inspection phase, n-dimensional test data to be inspected for abnormalities is obtained and compared to the reference template to detect abnormalities.

Method for automatic screening of abnormalities

A method, for practice on a computer, for interpreting two-dimensional images of three-dimensional scenes is disclosed. Descriptive labels are assigned to the vertex, edge and face elements of the image. A process of constraint satisfaction and propagation is carried out between image elements that are linked together with the effect of pruning away locally inconsistent labels at each element. The remaining labels assigned to the image elements are both locally and globally consistent.

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Pleasanton, CA, United States of America

Van-Duc Nguyen