Space scanning based alignment signals sampling synchronous control method

Abstract

This invention discloses one signal calibration sampling simultaneous control method based on the space scanning, which scans the transparent vertical graph grating along its front and back diagonal direction and processes the signals with high order polynomial approximation to get front and back two maximum light intensity and to trigger and sample the simultaneous calibration by use of the two position difference. The method realizes the light intensity signal and position signal intensity simultaneous measurement to ensure the simultaneous control on the light signal and position signal.

Description

technical field [0001] The invention belongs to the field of detection, control and error compensation of scanning speed or position in image signal processing, and specifically relates to a sampling synchronous control that can realize accurate synchronous measurement of alignment position signals and light intensity signals in alignment synchronous scanning of lithography machines method. Background technique [0002] Precision detection technology is the foundation of modern industry and information processing technology. In the alignment control technology of lithography machines, the detection and processing of light intensity signals and position signals require precise detection methods to obtain precise synchronization information through calibration, so that The measured value is closer to the true value. In the prior art, the alignment gratings are only scanned in the x-direction or the y-direction, and no high-order polynomial approximation is performed on the sc...

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Problems solved by technology

In the prior art, the alignment grating is only scanned in the x direction or the y direction, and no high-order polynomial approximation is performed on the scanning signal, and due to the fact that the two alignment gratings are controlled to move in the x direction and the y direction during the actual alignment scan Due to the inconsistency and non-uniformity of the speed and acceleration of the linear motor, the error of alignment scanning is often very large, which cannot guarantee high-precision detection of light intensity signals and position signals, let alone achieve high-precision synchronous detection to obtain light intensity information and location information

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