Projection optics

Abstract

Disclosed is a projection optical system. The system comprises a light axle; a concave spherical reflecting mirror; a pair of glass prism, wherein each prism has corresponding first and second plane, the second plane contacts the first converging lens plane along the direction opposite to the light axle, and the first plane orientates to the object plane and the image plane; a converging lens group including a flat convex lens and a meniscus lens, wherein the convex surface orientates to the reflecting mirror; a telescope lens group including a concave-convex lens, a biconvex lens and a biconcave lens; a concave reflecting mirror which concave surface orientates to the object.

Description

Technical field [0001] The invention belongs to photolithography technology in integrated circuit manufacturing process, in particular to a projection optical system. Background technique [0002] With the continuous development of integrated circuits, the minimum line width of transistors continues to shrink. The gate length of transistors in advanced CMOS processes is already less than 0.1 microns. The continuous reduction of feature line width has led to a substantial increase in chip integration, but it has also brought great challenges to the optical lithography process. [0003] In order to obtain a smaller line width, people are also trying to use electron beam lithography, X-ray lithography and ion beam lithography and other alternative methods of optical lithography, but due to the cost, speed and difficulty in mask manufacturing, currently It is also difficult to compete with the optical lithography method, and the optical lithography method is still used in all ...

AI Technical Summary

Problems solved by technology

[0008] In addition, the total optical length in the 352 patent exceeds 1100mm, which will cause great difficulties in the environmental control (vibration reduction design and temperature control, etc.) of the entire projection objective lens system

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