A symmetrical bi-telecentric projection optical system and lithography equipment

Abstract

The invention discloses a symmetrical bi-telecentric projection optical system and lithography equipment. The projection optical system is used to image the figure in the object plane into the image plane, and includes a front group, an aperture stop and a rear group along the direction of its optical axis. The front group includes a first mirror group, a second mirror group and a third mirror group, the first mirror group has a negative refractive power, and the second mirror group and the third mirror group have a positive refractive power; the rear group Including the fourth mirror group, the fifth mirror group and the sixth mirror group, the fourth mirror and the fifth mirror group have positive refractive power, the sixth mirror group has negative refractive power; the front group and the rear group It is symmetrical with respect to the aperture stop and satisfies a certain relational expression. The projection optical system of the present invention can effectively correct various aberrations even when optical materials with excellent performance are used, expand the size of the field of view on the image side, and improve the imaging resolution; and the lens diameter is small, does not include aspherical lenses, and greatly increases the Reduce the difficulty and cost of processing, testing and calibration.

Description

technical field [0001] The present invention relates to an optical system of a lithographic equipment for microfabrication, in particular to a symmetrical bi-telecentric projection optical system and a lithographic equipment using the symmetrical bi-telecentric projection optical system, the symmetrical bi-telecentric projection optical system The projection optical system is mainly used in micro-electromechanical systems (MEMS, Micro-Electro-Mechanical System), photolithography systems such as semiconductors, solar cells, liquid crystals, and printed circuit boards, as well as projection optical systems for photolithography. Background technique [0002] With the development of projection lithography technology, the performance of the projection optical system is gradually improved, and the projection optical system can already be applied to various fields such as circuit manufacturing. Projection lithography technology can also be used in technical fields such as semicondu...

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Problems solved by technology

[0004] Chinese patent CN98113037.2 (announcement date: July 23, 2003) is a double Gaussian optical system with telecentric image space. Since the patent uses two glued surfaces, in high-yield projection lithography equipment, the lens The adhesive will produce great deformation or even denaturation, resulting in reduced optical imaging performance, shortened service life of the projection lens, and does not meet the requirements of lithography technology

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