Alignment system for photoetching device and stage jointing grating system

Abstract

This invention discloses a kind of optical-mechanical system which is used in photoetching machine and on it, and its matching system includes light source module supplying light. Transmitting light beam, vertical illumination crystal plate cyclicity optical structure alignment mark lighting unit. To collect alignment mark the multilevel diffracted ray by using microobjective. To realize the multi-wavelength separated by using the polychromatic light separated system. To correspond the positive and negative diffraction spectrum of the alignment mark with the imaging units by using level-bonded grating system. To measure the changing of the light intensive and the phase for the several wave-length and the levels spectrum spot by using the differential Mohr-message detection method, so we can got the detective unit of the alignment mark message. The level-bonded grating system includes the grating, the reflecting mirror and the prism, to overlay the +1-+n level and the -1--n level of the alignment mark message mark with the positive and negative diffraction spot. It can supply highly alignment accuracy and stability.

Description

technical field [0001] The invention relates to a lithographic device in the field of integrated circuit IC or other micro device manufacturing, and relates to an alignment system for the lithographic device and a level-combined grating system thereof. Background technique [0002] Lithography equipment is mainly used in the manufacture of integrated circuits IC or other micro-devices. With a photolithographic apparatus, multilayer masks with different mask patterns are sequentially imaged in precise alignment on a photoresist-coated wafer, such as a semiconductor wafer or an LCD panel. [0003] IC devices manufactured by photolithography technology require multiple exposures to form multilayer circuits in the wafer. For this reason, an alignment system is required in the photolithography device to achieve precise alignment between the mask and the wafer. When the feature size "CD" is required to be smaller, the requirements for overlay accuracy "Overlay" and the resulting ...

AI Technical Summary

Problems solved by technology

Although this technology uses two sets of alignment marks, coarse and fine, to improve the alignment capture range, on the one hand, the two-stage drive increases the complexity of the drive system and also increases the instability factors that affect the alignment accuracy; On the one hand, this technology is only suitable for proximity lithography. If it is used for projection lithography, the above-mentioned problem of low alignment accuracy still exists

Images