Calibration device for aligning system of stepper and its calibration method

Abstract

The invention provides a calibrating device and method used for the aligning system of a stepping photoetching machine. The aligning system consists of a locating platform and a control computer. The calibrating device consists of a calibrating board and a calibrating marker. The calibrating board is provided with the common calibrated points distributed in a matrix way on the calibrating board and locating calibrated points distributed oddly and evenly on the calibrating board. The calibrating marker is positioned in the range of the calibrating board without calibrated points or on the locating platform. The calibrating method can realize an alignment of the aligning system by establishing a relationship between the coordinate system of the calibrating board and the image coordinate on the control computer and establishing a relationship between the coordinate system of the calibrating board and the external coordinate system of the locating platform to establish a relationship between the image coordinate system on the control computer and the external coordinate system of the locating platform. The calibrating device and method of the invention is compatible with the aligning system of the stepping photoetching machine, and has higher aligning precision and reliability.

Description

technical field [0001] The invention relates to the field of an alignment system of a stepper lithography machine, in particular to a calibration device and a calibration method for an automatic alignment system of a stepper lithography machine. Background technique [0002] The function of the stepper is to project the circuit pattern drawn on the reticle onto the surface of the exposure object such as a silicon wafer coated with a photosensitive material by means of optical projection. Then, the pattern transfer between the mask plate and the exposure object is realized through etching and other processes. Since chips are composed of multiple layers of circuits, integrated circuit chips usually require multiple exposures to complete. To ensure precise positional relationship between different circuit layers, precise alignment between mask and exposure object must be achieved during projection exposure. [0003] In the projection exposure system of the current stepper lit...

AI Technical Summary

Problems solved by technology

[0007] The purpose of the present invention is to provide a calibration device and calibration method that can be used for the alignment system of a stepper lithography machine, which can solve the algorithm defects of the alignment system in the current stepper lithography machine based on the perspective projection relationship, and the higher precision calibration. Barebone systems are difficult to implement, alignment accuracy and reliability are easily affected, and the calibration device does not meet the installation requirements of the stepper lithography machine.

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