Agilent Technologies, Inc.

David C Chu

William Clay Schluchter

Lee Charles Kalem

Evan R Whitney

Janet L Yun

Alan B Ray

Carol Courville

Nhan Tri Nguyen

Douglas P Woolverton

Louis F Mueller

Raymond Yeung

Jeffrey A Young

Matthew D Tenuta

A location system and a location system on a chip (LCoS) and method are described.

System architecture for sensing an absolute position using a target pattern

A system for sensing an absolute two-dimensional position of an object having a two-dimensional target pattern thereon comprises a sensor and a controller. The sensor is for capturing an image of a subset of the target pattern. The controller is for generating a first image vector representing summations of rows of pixel values from the image, and a second image vector representing summations of columns of pixel values from the image. The controller is configured to determine an absolute two-dimensional position of the subset of the target pattern with respect to the origin of the target pattern based on the first image vector, the second image vector and target vectors that represent the target pattern.

System for sensing an absolute position in two dimensions using a target pattern

A method for non-linearity compensating interferometer position data generated from a measurement signal includes generating a first set of non-linearity parameters based on received digital position values. The method includes sensing whether a low velocity condition exists. A first one of the non-linearity parameters is updated based on an estimated magnitude of the measurement signal if the low velocity condition exists. At least one digital position value is compensated based on the updated non-linearity parameter if the low velocity condition exists.

System and method for interferometer non-linearity compensation

A system for sensing an absolute position in two dimensions includes a target having a two-dimensional target pattern. A sensor captures an image of a first subset of the target pattern. A controller generates a first image vector representing summations of rows of pixel values from the image, and a second image vector representing summations of columns of pixel values from the image. The controller is configured to determine an absolute two-dimensional position of the first subset with respect to an origin of the target pattern based on the first and the second image vectors and a plurality of target vectors that represent the target pattern.

A system and method for acquiring position information of a movable apparatus relevant to a specific axis is disclosed. In one embodiment, an interferometer generates first and second beams and various beam-steering members are located to define beam path segments for the two beams, but no beam path segment varies in length in unity with displacements of the movable apparatus along the specific axis. In another or the same embodiment, each beam path segment in which the first beam either impinges or has been reflected from the movable apparatus is symmetrical to a corresponding beam path segment of the second beam. The movable apparatus may be a wafer stage in which the 'specific axis' is the exposure axis of a projection lens, but with all optical members which cooperate with the stage being located beyond the ranges of the wafer stage in directions perpendicular to the lithographic exposure axis.

System and method of using a side-mounted interferometer to acquire position information

A method of digitizing first and second signals in imperfect quadrature for obtaining characteristic parameters of the first signal comprises providing a first signal, the first signal comprising an inphase quasi-sinusoidal analog signal. The method comprises providing a second signal, the second signal comprising a quadrature signal. The method comprises digitizing the first signal at a sampling rate, thereby generating a first plurality of sets of digital signal waveform samples and digitizing the second signal at the sampling rate, thereby generating a second plurality of sets of digital signal waveform samples. The method comprises digitally processing successive first and second sets of digital signal waveform samples to generate continually updated digital characteristic parameters representing a characteristic behavior of the first signal.

Phase digitizer for signals in imperfect quadrature

A system and method for compensating non-linearity of the high-velocity type manifested in heterodyne interferometer position data includes receiving a plurality of groups of digital position values. A plurality of groups of digital phase values from a measurement channel are received. A first group of the digital position values and digital phase values are digitally processed to generate a plurality of block data values. The plurality of block data values are digitally processed to generate at least one quasi-static non-linearity parameter. A second group of the digital position values are compensated based on the at least one quasi-static non-linearity parameter.

System and method for heterodyne interferometer high velocity type non-linearity compensation

A system and method for non-linearity compensating interferometer position data includes receiving a plurality of groups of digital position values. A first group of the digital position values are digitally processed to generate a plurality of data values. The plurality of data values are digitally processed to generate at least one quasi-static non-linearity parameter. A second group of the digital position values are compensated based on the at least one non-linearity parameter.

A system and method of digitizing characteristic parameters of a quasi-sinusoidal analog signal of unknown magnitude, frequency and phase-offset, includes digitizing the analog signal at a first sampling rate, thereby generating a plurality of sets of digital signal waveform samples. Successive sets of the digital signal waveform samples are digitally processed to generate continually updated digital characteristic parameters representing a characteristic behavior of the quasi-sinusoidal analog signal.

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Palo Alto, CA, United States of America

David C Chu