Raster polarization photomask plate and its application in projection photoetching system

Abstract

The grating polarization mask belongs to the further optimized design of the mask structure in the projection optical lithography system. It is characterized in that the grating polarization with a certain width and depth is etched on the mask feature pattern according to the characteristic line width of the feature pattern on the mask plate. The structure combines the grating structure that produces polarized light with the traditional mask, so that the mask itself has the function of outputting polarized light. The grating polarization mask controls the spatial coherence of the electric field by controlling the vector direction of the electric field vector, so as to improve the resolution The purpose, and the grating polarization structure on the grating polarization mask will make the linearly polarized imaging beams whose polarization directions are perpendicular to each other pass through the light-transmitting area adjacent to the opaque area, and the images of adjacent patterns will not appear on the silicon wafer. Interference effect is generated, so the proximity effect is small, which can further improve the resolution of projection optical lithography imaging lithography, and further tap the lithography resolution ability of short-wavelength high numerical aperture projection optical lithography imaging system, and projection lithography equipment does not need any Modifications for ultra-deep sub-micron and hundreds of nanometer projection optical lithography.

Description

Technical field [0001] The invention is a grating polarization mask, which belongs to the further optimized design of the mask structure in the step-and-repeat projection optical lithography system and the step-and-scan projection optical lithography system. Background technique [0002] With the development of modern microelectronics technology in the direction of high-integration ultra-micronization, the continuous improvement of the lithography resolution level that can be achieved by the projection lithography equipment for producing fine graphics has become the core problem that modern lithography technology urgently needs to solve. Since the "next generation" lithography technology (such as EUV lithography, electron beam projection lithography, X-ray lithography, etc.) is still in the research stage, and its technology, equipment and processes are very expensive, coupled with optical lithography Therefore, the research, development and application of lithographic resol...

AI Technical Summary

Problems solved by technology

The application of phase-shift mask technology improves the resolution to some extent, but with the reduction of the basic period of the lithography line, the increase of the numerical aperture of the projection lithography objective lens, the shortening of the exposure wavelength, and the polarization-based vector diffraction The influence of the photolithography effect on the lithographic pattern is increasing, and the phase shift mask cannot guarantee high-quality imaging; and the design and position of the optimal phase shifter are difficult to place, and the manufacturing cost is high. The above-mentioned deficiencies are difficult to meet the needs

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