A projection objective lens focal plane shape measurement marking device and its application

Abstract

The present invention provides a projection object lens focal plane shape measurement marking device and application, which contains a chrome-plated area, a light-transmitting area, and a phase groove area, wherein: the width ratio of the chrome-plated area, the light-transmitting area, and the phase groove area is 2:1: 1; The phase groove region has a phase depth of 90°. When in use, make a test mask with measurement marks that can improve the measurement resolution of the focal plane shape of the projection objective lens, and the measurement marks are evenly distributed in the entire exposure field of view; The real focal plane shape of the projection objective lens can be obtained by combining the corresponding relationship between the defocus amount and the interference fringe offset of the formula; in the focal plane control process of the lithography machine, the silicon wafer exposure field will be The focal plane data of the projection objective lens is subtracted from the surface height data of the silicon wafer, and then the obtained result is plane-fitted to complete the ultra-high-precision focal plane control of the lithography machine.

Description

technical field [0001] The invention belongs to the technical field of ultra-precision measurement, and relates to a measuring marking device for the focal plane shape of a projection objective lens and an application thereof. Background technique [0002] The development of the integrated circuit industry has always followed Moore's Law, that is, the integration level doubles every 18 months, and the feature size (ie resolution) of the device shrinks to 1 / 2 of the original value every 18 months. The improvement of resolution can be achieved by shortening the exposure wavelength and increasing the numerical aperture, but both will lead to a sharp shortening of the focal depth of lithography; at the same time, the flatness of the silicon wafer brought about by the use of large diameter silicon wafers , thickness uniformity and other issues require lithography equipment to have a large depth of focus to complete the effective exposure of silicon wafers; the contradiction betwe...

AI Technical Summary

Problems solved by technology

[0005] The technical problem of the present invention is to overcome the deficiencies in the prior art, provide a measurement marking device for measuring the real focal plane shape of the projection objective lens, and provide the application of the measurement marking device in improving the control accuracy of the focal plane of the lithography machine, so as to solve the problem of The problem that the shape of the focal plane of the projection objective lens affects the control accuracy of the focal plane of the lithography machine

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