A high na projection objective lens

Abstract

The invention provides a high-NA projection lens used for enabling images of a mask surface to be formed in a silicon wafer surface. The high-NA projection lens is composed of a first unit, a second unit, a third unit, a fourth unit, a fifth unit, a sixth unit, a seventh unit, an eighth unit, a ninth unit and a tenth unit. The first unit L1, the second unit L2, the third unit L3, the fifth unit L5 and the eighth unit L8 have positive focal power. The seventh unit L7, the ninth unit L9 and the tenth unit L10 have negative focal power. The fourth unit L4 and the sixth unit L6 are plane mirrors, and the angle between each plane mirror and the horizontal plane is 45 degrees. By the high-NA projection lens, an object is formed to be an image where the object is shrunk by one fourth. The high-NA projection lens has the advantages of the high NA, high definition, compact structure, good imaging quality and the like.

Description

technical field

[0001] The invention relates to an immersion type ultraviolet optical system used in a lithography process and a semiconductor element manufacturing device, belonging to the technical field of projection optics. Background technique

[0002] Lithography is an integrated circuit manufacturing technology. It uses the principle of optical projection image to transfer the high-resolution graphics on the mask plate to the optical exposure process of the rubber-coated silicon wafer by means of exposure. Almost all integrated circuits Fabrication is done using optical projection lithography. Initially, semiconductor devices were manufactured using contact lithography technology in which masks were attached to silicon wafers. In 1957, contact lithography technology realized the manufacture of DRAM with a feature size of 20 microns. After that, the semiconductor industry introduced proximity lithography technology with a certain gap between the mask and the silicon ...

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