Excimer laser

Abstract

The invention discloses an excimer laser, comprising a seed cavity, an amplifying cavity and a light path transmission structure. The seed cavity is used for outputting seed laser; the amplifying cavity is used for amplifying the energy of the seed laser; the light path transmission structure is used for guiding the transmission of the laser, wherein the light path transmission structure comprises a first triangular prism, a second triangular prism and a third triangular prism. By adopting triangular prisms with special angles and special placing manners to the triangular prisms, the excimer laser of the invention could achieve mutual compensation of phase difference of a P light and an S light so that the light path transmission structure will not generate additional phase difference to achieve the goal of enabling the polarization state of the laser which is finally output and the polarization state of the seed laser output from a discharging cavity to be consistent and holding the stability of the polarization states of the laser.

Description

technical field [0001] The invention belongs to the technical field of lasers, in particular to an excimer laser. Background technique [0002] With the gradual reduction of lithography feature size and the increase of numerical aperture in the current integrated circuit manufacturing, the polarization characteristics of illumination light have an increasing impact on the final lithography imaging quality. Therefore, excimer lasers for illumination in lithography machines The polarization characteristic control of the output laser becomes very necessary. In the lithography imaging optical system, the polarized illumination light has high spatial imaging contrast and good imaging quality, so the excimer laser light source for lithography is required to have a very high laser polarization degree. At the same time, in order to facilitate the adjustment and control of the polarization direction of the subsequent optical path, it is also necessary to keep the polarization direct...

AI Technical Summary

Problems solved by technology

It can be seen from the calculation of the phase change that the components of the currently disclosed optical path transmission structure basically cannot realize the phase mutual compensation effect, so the seed light output by the discharge cavity will be introduced into the additional phase difference when it is transmitted in the optical path transmission structure. Thus changing the initial polarization state of the seed light

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