Magnification adjusting method of symmetric type double telecentric projection optical system

Abstract

The invention discloses a magnification adjusting method of a symmetric type double telecentric projection optical system. The magnification adjusting method comprises the following steps: 1, providing the symmetric type double telecentric projection optical system which comprises a front group, an aperture diaphragm and a rear group in an optical axis direction, wherein the front group comprises a first lens group, a second lens group and a third lens group, the first lens group has negative focal power, the second lens group and the third lens group have positive focal power, the rear group comprises a fourth lens group, a fifth lens group and a sixth lens group, the fourth lens group and the fifth lens group have positive focal power, the sixth lens group has negative focal power, and the front group and the rear group are symmetrical around the aperture diaphragm and meet a certain relational expression; 2, simultaneously moving lens displacement in the first lens group and the sixth lens group so as to adjust projection magnification of the optical system. With the adoption of the magnification adjusting method, aberrations can be effectively corrected by using an optical material with excellent performance, so that the size of field angle in image space is enlarged, and the imaging resolution ratio is increased; meanwhile, the lenses are small in aperture and exclude aspheric surface lenses, so that the difficulty and the cost for processing, detecting and aligning can be greatly reduced.

Description

technical field [0001] The present invention relates to a method for adjusting the magnification of an optical system of a lithographic equipment for micromachining, and in particular to a method for adjusting a magnification of a symmetrical bi-telecentric projection optical system. The symmetrical bi-telecentric projection optical system is mainly used in micro Electromechanical systems (MEMS, Micro-Electro-Mechanical System), photolithography systems such as semiconductors, solar cells, liquid crystals, printed circuit boards, and 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 semiconductors, solar cells, liquid crystals, and prin...

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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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