Device and method for detecting pattern positioning precision

Abstract

The invention discloses a figure locating precision detecting device and a detecting method thereof, wherein the device comprises a phase shift module, a transmission focusing optical module, a mask stage, a beam-splitting prism, a collimation module, a spectroscope arranged at 45 degrees, an aligning sensor positioned on the first exit surface of the spectroscope, an illuminated light source module and a laser source module which are arranged in turn along a detecting light path; the exit light of the illuminated light source module irradiates the upper surface of a mask plate through the beam-splitting prism; the exit light of the laser source module is split into reference light and transmitted light through a beam-splitting module; the reference light irradiates the beam-splitting prism via a reference light monomode fiber; the transmitted light irradiates the transmission focusing optical module via a transmitted light monomode fiber; the second exit surface of the spectroscope is provided with an imaging module and an image sensor; in addition, the device also comprises a main controller connected with the parts. The device can measure the accurate change of figure position and reduces the size of an optical detecting element along with high detecting precision and convenient operation.

Description

technical field [0001] The invention relates to a pattern positioning device and a using method thereof, in particular to a mask plate pattern positioning accuracy detection device and a detection method for a photolithography machine. Background technique [0002] In the field of semiconductor lithography, the production of semiconductor components generally requires multi-layer exposure. Different layers require their own reticles, and strict overlay accuracy is required between reticles of different layers, which is a limitation of product performance. An important factor, in order to improve the yield rate of the product, it is necessary to accurately measure the positioning accuracy of the pattern on the reticle. [0003] The current positioning accuracy of the mask pattern is to calculate the position of the center of the image by accurately locating the edge of the image. The principle is to focus the spot to a small point through an optical microscope and an electron...

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Problems solved by technology

[0004] The shortcoming of above-mentioned device is: (1) owing to needing fine line is resolved and imaging, needs to use shorter wavelength and larger numerical aperture (NA), the wavelength of LEICA is 360-410nm, and numerical aperture is maximum 0.9, This brings greater difficulties to optical processing and manufacturing; (2) When measuring small lines, the working distance when choosing to use a large numerical aperture is particularly short, only 250um, so that it cannot be measured when there is a protective film on the mask; (3) In order to combine the autofocus system, alignment system and imaging system into one system and not affect each other, the system needs to use three bands of wavelengths, the imaging system is 360-410nm, the autofocus system is 903nm, the alignment The system is 440-770nm, which increases the difficulty of optical coating; (4) Since the positioning information is jointly determined by the positioning error of the image sensor and the positioning of the mask stencil measurement system, the image positioning error on the image sensor will greatly affect the The final error result; (5) Image sensor imaging optical path error will also lead to positioning error

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