Laser interferometer mirror shape measurement method and photolithography device

Abstract

The present invention provides a method for measuring a topography of a laser interferometer reflector and a photoetching device. The measuring method comprises the following steps of: generating at least two light spots on a substrate, recording vertical heights of all light spots at the moment; moving a wafer stage several times in a same direction on a horizontal plane, moving one of the lightspots to a position where another light spot is located before moving every time the wafer stage is moved, a difference value between the vertical height of the other light spot before moving and thevertical height of the light spot after moving is a height change of a corresponding point on a long-strip mirror, and the change in height of a plurality of points on the long-strip mirror constitutes a shape change of a mirror surface of the long-strip mirror in the direction. According to the method for measuring topography of reflector of laser interferometer and the photoetching device, the standard interferometer used for calibration is removed, and the method is convenient to use on an assembled photoetching machine; at least two light spots which are not necessarily equal in spacing are arranged, so that an measurement precision is improved, and an number of light spots of FLS is not greatly increased; and an substrate measurement area is reduced, so as to shorten the time spent for calibration.

Description

technical field [0001] The invention relates to the field of semiconductors, in particular to a method for measuring the shape of a laser interferometer mirror and a photolithography device. Background technique [0002] A projection lithography machine is a device that projects the pattern on the mask onto the upper surface of the substrate through a projection objective lens. [0003] In the exposure process, the substrate is a kind of substrate, and the substrate will be uploaded to the workpiece table and reach the designated position through the movement of the workpiece table, and the workpiece table is usually positioned by a laser interferometer. The shape of the mirrors of laser interferometers, including strip mirrors and oblique mirrors, will affect the measured value of the interferometer, thereby affecting the positioning of the workpiece table. The general oblique reflector is a 45° reflector. [0004] There are many different technical solutions in the prior...

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Problems solved by technology

However, the averaging method cannot completely eliminate the error caused by the substrate topography, and such measurement results will inevitably include changes in the substrate topography, making the measurement results inaccurate

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